Use destructures and refactor code for readability (#4844)

* Use destructuring for readability and optimzations at for loop length property

* Destructure variables for easy maintainability of code

* PR review fix

* refactor: fix linting

* Use destructures and refactor code for better readability

* Remove merge conflict line

* lint before commit

src/language-css/parser-postcss.js

@@ -480,7 +480,7 @@ function parseNestedCSS(node) {
 
 function parseWithParser(parser, text) {
   const parsed = parseFrontMatter(text);
-  const frontMatter = parsed.frontMatter;
+  const { frontMatter } = parsed;
   text = parsed.content;
 
   let result;