removed unused files and made minor fixed to the docs

docs/00_Overview.md

@@ -16,8 +16,6 @@ A Noja program is a sequence of statements separated by semi-colons (with some e
 
 (You may note that there is no import statement! This is because the ability to import other files is exposed through a built-in function.)
 
-Whitespace doesn't matter.
-Comments starts with `#` and end with the line.
+If not in string literals, whitespace doesn't matter.
 
-## Notable features
-* No exceptions
+Comments starts with `#` and end with the line.

docs/04_Functions.md

@@ -200,7 +200,7 @@ fun someFunction(optionalNumber: int | float | None) {
 }
 ```
 
-Default arguments are evaluated before the type hints, therefore when `none` is provided argument, no error is triggered even when it wasn't allowed as a type if a proper default argument was provided. If the default value doesn't result in a valid type, an error is triggered.
+Default arguments are evaluated before the type hints, therefore when `none` is provided as argument value, no error is triggered if a proper default argument was specified, even when it wasn't allowed as a type. If the default value doesn't result in a valid type, an error is triggered.
 
 ```py
 fun someFunction(a: int = 4) {}