Update to_gc_num.mdx (#505)

* Update to_gc_num.mdx

adding details about invalid GC string

* Update to_gc_num.mdx

* Update to_gc_num.mdx

* Update to_gc_num.mdx

* Update to_gc_num.mdx

* Update to_gc_num.mdx

* Update to_gc_num.mdx

* Update to_gc_num.mdx

* Apply suggestions from code review

Co-authored-by: Bryn Ward-Leikis <ward.leikis@gmail.com>

---------

Co-authored-by: matr1x <53655672+matr1x-hackmud@users.noreply.github.com>
Co-authored-by: Bryn Ward-Leikis <ward.leikis@gmail.com>

Author: 3 people

docs/scripting/scripts.lib/to_gc_num.mdx

@@ -20,6 +20,15 @@ The formatted GC string to be turned into a number.
 
 Returns a number.
 
+For invalid `gc_string` values, the following object is returned:
+
+```js
+{
+  ok: false,
+  msg: "GC string \"" + gc_string + "\" is not in correct format. Example GC strings: \"1M234K567GC\", \"1B5KGC\", \"2MGC\", \"9GC\"."
+}
+```
+
 ## Example
 
 ```js