Fix code examples and improve documentation

docs/language/composite-types.mdx

@@ -79,7 +79,7 @@ of the composite type requires them.
 
 Composite types can only be declared within [contracts](../contracts)
 and not locally in functions.
-They can also not be nested.
+
 
 Resource must be created (instantiated) by using the `create` keyword
 and calling the type like a function.
@@ -924,7 +924,7 @@ res.value
 // This function is invalid, because it does not always use the resource parameter,
 // which would cause a loss of the resource.
 //
-pub fun sometimesDestroy(resource: @SomeResource, destroy: Bool) {
+pub fun sometimesDestroy(resource: @SomeResource, destroyResource: Bool) {
     if destroyResource {
         destroy resource
     }

docs/language/functions.mdx

@@ -369,7 +369,7 @@ A function may refer to variables and constants of its outer scopes
 in which it is defined.
 It is called a closure, because
 it is closing over those variables and constants.
-A closure can can read from the variables and constants
+A closure can read from the variables and constants
 and assign to the variables it refers to.
 
 ```cadence

docs/language/restricted-types.md

@@ -45,11 +45,11 @@ pub resource Counter: HasCount {
 // Create an instance of the resource `Counter`
 let counter: @Counter <- create Counter(count: 42)
 
-counterRef.count  // is `42`
+counter.count  // is `42`
 
-counterRef.increment()
+counter.increment()
 
-counterRef.count  // is `43`
+counter.count  // is `43`
 
 // Move the resource in variable `counter` to a new variable `restrictedCounter`,
 // but typed with the restricted type `Counter{HasCount}`: