std.mdの関数群の見出しレベルを上げる

docs/en/references/std.md

@@ -12,178 +12,176 @@ Represents a standard constant named `Core:v`.
 Represents a standard function named `Core:type`.  
 It takes one argument of type value (i.e., any type) named `v` and returns a value of type str (string type).
 
-## List
+## std
 
-### std
-
-#### @print(_message_: str): void
+### @print(_message_: str): void
 Displays a string on the screen.
 
-#### @readline(_message_: str): str
+### @readline(_message_: str): str
 Accepts string input.  
 
-### :: Core
+## :: Core
 
-#### #Core:v
+### #Core:v
 Type: `str`  
 Version of AiScript runtime that's currently running.  
 
-#### @Core:type(_v_: value): str
+### @Core:type(_v_: value): str
 Get the type name of the value.  
 
-#### @Core:to_str(_v_: value): str
+### @Core:to_str(_v_: value): str
 Obtains a string representing a value.  
 
-#### @Core:sleep(_time_: num): void
+### @Core:sleep(_time_: num): void
 Wait for the specified time (milliseconds).
 
-#### @Core:abort(_message_: str): never
+### @Core:abort(_message_: str): never
 Aborts the execution.
 
-### :: Util
+## :: Util
 #### @Util:uuid(): str
 Generates new UUID.
 
-### :: Json
-#### @Json:stringify(_v_: value): str
+## :: Json
+### @Json:stringify(_v_: value): str
 Generate JSON string.
 
-#### @Json:parse(_json_: str): value
+### @Json:parse(_json_: str): value
 Parse JSON into object. Returns an error type value (`name`=`'not_json'`) if the argument is not parsable as JSON. 
 
-#### @Json:parsable(_str_: str): bool
+### @Json:parsable(_str_: str): bool
 Determines if a string can be parsed as JSON. Exists for historical reasons.
 
-### :: Date
-#### @Date:now(): num
+## :: Date
+### @Date:now(): num
 Returns current date. 
 
-#### @Date:year(_date_?: num): num
+### @Date:year(_date_?: num): num
 Get the year of the time.  
 If _date_ is passed, the year corresponding to _date_,  
 If not passed, the year of the current time is returned.    
 
-#### @Date:month(_date_?: num): num
+### @Date:month(_date_?: num): num
 Get the month of the time.  
 If _date_ is passed, the month corresponding to _date_,  
 If not passed, the month of the current time is returned.    
 
-#### @Date:day(_date_?: num): num
+### @Date:day(_date_?: num): num
 Get the day of the current time.  
 If _date_ is passed, the day corresponding to _date_,  
 If not passed, the day of the current time is returned.
 
-#### @Date:hour(_date_?: num): num
+### @Date:hour(_date_?: num): num
 Get the hour of the current time.  
 If _date_ is passed, the time corresponding to _date_,  
 If not passed, the current time is returned.
 
-#### @Date:minute(_date_?: num): num
+### @Date:minute(_date_?: num): num
 Get the minutes of the current time.  
 If _date_ is passed, the minute corresponding to _date_,  
 If not passed, the minute of the current time is returned.
 
-#### @Date:second(_date_?: num): num
+### @Date:second(_date_?: num): num
 Get the seconds of the current time.  
 If _date_ is passed, the second corresponding to _date_,  
 If not passed, the second of the current time is returned.
 
-#### @Date:millisecond(_date_?: num): num
+### @Date:millisecond(_date_?: num): num
 Get the milliseconds of the current time.  
 If _date_ is passed, the millisecond corresponding to _date_,  
 If not passed, the millisecond of the current time is returned.
 
-#### @Date:parse(_date_: str): num
+### @Date:parse(_date_: str): num
 Generates a numeric value representing a date/time from a string that can be interpreted as a date.  
 Interpretation depends on [JavaScript's Date constructor](https://developer.mozilla.org/ja/docs/Web/JavaScript/Reference/Global_Objects/Date/Date).  
 If the argument is not interpretable as a date, it returns a value of type error (`name`=`'not_date'`).
 
-#### @Date:to_iso_str(_date_?: num, _time_offset_?: num): str
+### @Date:to_iso_str(_date_?: num, _time_offset_?: num): str
 Returns a string with _date_ in extended notation ISO format.  
 If _date_ is not passed, the current time is used.  
 _time_offset_ is the time difference (in minutes) from UTC.  
 If _time_offset_ is not passed, the local one is used.
 
-### :: Math
+## :: Math
 →[Click here](std-math.md)
 
-### :: Num
-#### @Num:from_hex(_hex_: str): num
+## :: Num
+### @Num:from_hex(_hex_: str): num
 Return number from a hexadecimal string.  
 
-### :: Str
-#### #Str:lf
+## :: Str
+### #Str:lf
 Type: `str`
 Line feed (LF).
 
-#### @Str:lt(a: str, b: str): num
+### @Str:lt(a: str, b: str): num
 Returns -1 if a < b, 0 if a == b, or 1 if a > b.
 Can be used as a comparison function for arr.sort.
 
-#### @Str:gt(a: str, b: str): num
+### @Str:gt(a: str, b: str): num
 Returns -1 if a > b, 0 if a == b, or 1 if a < b.
 Can be used as a comparison function for arr.sort.
 
-#### @Str:from_codepoint(codepoint: num): str
+### @Str:from_codepoint(codepoint: num): str
 Generates characters from Unicode codepoints.  
 _codepoint_ must be greater than or equal to 0 and less than or equal to 10FFFFF<sub>16</sub>.
 
-#### @Str:from_unicode_codepoints(_codePoints_: arr&lt;num&gt;): str
+### @Str:from_unicode_codepoints(_codePoints_: arr&lt;num&gt;): str
 Generates characters from an array of numbers representing a sequence of Unicode code points.  
 Each element of __codePoints_ must be greater than or equal to 0 and less than or equal to 10FFFFFF<sub>16</sub>.
 
-#### @Str:from_utf8_bytes(_bytes_: arr&lt;num&gt;): str
+### @Str:from_utf8_bytes(_bytes_: arr&lt;num&gt;): str
 Generates characters from an array of numbers representing a UTF-8 byte sequence.  
 Each element of _bytes_ must be greater than or equal to 0 and less than or equal to 255.
-### :: Uri
-#### @Uri:encode_full(uri: str): str
+## :: Uri
+### @Uri:encode_full(uri: str): str
 Returns a string with uri encoded as a URI. The following characters are not encoded:  
 `A-Z a-z 0-9 - _ . ! ~ * ' ( ) ; , / ? : @ & = + $ #`
 
-#### @Uri:encode_component(text: str): str
+### @Uri:encode_component(text: str): str
 Returns a string with text encoded as a URI component. The following characters are not encoded:  
 `A-Z a-z 0-9 - _ . ! ~ * ' ( )`
 
-#### @Uri:decode_full(encoded_uri: str): str
+### @Uri:decode_full(encoded_uri: str): str
 Returns a string that decodes encoded_uri as an encoded URI.  
 Escape sequences corresponding to the following characters are not decoded:  
 `; , / ? : @ & = + $ #`
 
-#### @Uri:decode_component(encoded_text: str): str
+### @Uri:decode_component(encoded_text: str): str
 Returns a string that decodes encoded_text as an encoded URI component.  
 
-### :: Arr
-#### @Arr:create(_length_: num, _initial_?: value): arr
+## :: Arr
+### @Arr:create(_length_: num, _initial_?: value): arr
 Creates an array of length `length`.  
 The array will be filled with _initial_ if given, otherwise with `null`.  
 
-### :: Obj
-#### @Obj:keys(_v_: obj): arr
-#### @Obj:vals(_v_: obj): arr
-#### @Obj:kvs(_v_: obj): arr
+## :: Obj
+### @Obj:keys(_v_: obj): arr
+### @Obj:vals(_v_: obj): arr
+### @Obj:kvs(_v_: obj): arr
 Returns an array of object keys, values, and key/value pairs.
 
-#### @Obj:get(_v_: obj, _key_: str): value
+### @Obj:get(_v_: obj, _key_: str): value
 
-#### @Obj:set(_v_: obj, _key_: str, _val_: value): null
+### @Obj:set(_v_: obj, _key_: str, _val_: value): null
 
-#### @Obj:has(_v_: obj, _key_: str): bool
+### @Obj:has(_v_: obj, _key_: str): bool
 
-#### @Obj:copy(_v_: obj): obj
+### @Obj:copy(_v_: obj): obj
 Generates the copy of the object.
 
-#### @Obj:merge(_o1_: obj, _o2_: obj): obj
+### @Obj:merge(_o1_: obj, _o2_: obj): obj
 Returns a merged version of the two objects.
 
-### :: Error
-#### @Error:create(_name_: str, _info_?: value): error
+## :: Error
+### @Error:create(_name_: str, _info_?: value): error
 Create error type value.
 
-### :: Async
-#### @Async:interval(_interval_: num, _callback_: fn, _immediate_?: bool): fn
+## :: Async
+### @Async:interval(_interval_: num, _callback_: fn, _immediate_?: bool): fn
 Calls the callback function at the specified period.  
 Returns a stop function.  
 
-#### @Async:timeout(_delay_: num, _callback_: fn):
+### @Async:timeout(_delay_: num, _callback_: fn):
 Calls the callback function after the specified time has elapsed.  
 Returns a stop function as the return value.