chore: update links from contrib to main org (#7672)

* chore: update links from contrib to main org

* fix: new test urls

Author: evenstensberg

src/content/awesome-webpack.mdx

@@ -71,7 +71,7 @@ _People passionate about Webpack (In no particular order)_
 #### Styles
 
 - [Style Loader](https://github.com/webpack/style-loader): Style loader module for Webpack. -- _Maintainer_: `Webpack Team` [![Github][githubicon]](https://github.com/webpack)
-- [PostCSS Loader](https://github.com/postcss/postcss-loader): PostCSS loader for Webpack. -- _Maintainer_: `PostCSS Team` [![Github][githubicon]](https://github.com/postcss) [![Twitter][twittericon]](https://twitter.com/PostCSS)
+- [PostCSS Loader](https://github.com/webpack/postcss-loader): PostCSS loader for Webpack. -- _Maintainer_: `PostCSS Team` [![Github][githubicon]](https://github.com/postcss) [![Twitter][twittericon]](https://twitter.com/PostCSS)
 - [CSS Loader](https://github.com/webpack/css-loader): CSS loader module for Webpack. -- _Maintainer_: `Webpack Team` [![Github][githubicon]](https://github.com/webpack)
 - [SASS Loader](https://github.com/webpack/sass-loader): SASS loader for Webpack. -- _Maintainer_: `Jorik Tangelder` [![Github][githubicon]](https://github.com/jtangelder) [![Twitter][twittericon]](https://twitter.com/jorikdelaporik)
 - [Less Loader](https://github.com/webpack/less-loader): Less loader module for Webpack. -- _Maintainer_: `Webpack Team` [![Github][githubicon]](https://github.com/webpack)

src/remark-plugins/remark-cleanup-readme/index.test.mjs

@@ -39,7 +39,7 @@ describe('cleanup readme', () => {
   });
 
   it('should clean up nested div[align="center"] block ', () => {
-    // see https://github.com/webpack-contrib/postcss-loader/blob/master/README.md
+    // see https://github.com/webpack/postcss-loader/blob/master/README.md
     const mdxText = `
 <div align="center">
   <img

src/utilities/process-readme.test.mjs

@@ -31,19 +31,19 @@ describe('processReadme', () => {
   it('rewrite relative url', () => {
     const options = {
       source:
-        'https://raw.githubusercontent.com/webpack-contrib/postcss-loader/master/README.md',
+        'https://raw.githubusercontent.com/webpack/postcss-loader/main/README.md',
     };
     const loaderMDData =
       'See the file [`./src/config.d.ts`](./src/config.d.ts).';
     expect(processReadme(loaderMDData, options)).toEqual(
-      'See the file [`https://github.com/webpack-contrib/postcss-loader/blob/master/src/config.d.ts`](https://github.com/webpack-contrib/postcss-loader/blob/master/src/config.d.ts).'
+      'See the file [`https://github.com/webpack/postcss-loader/main/src/config.d.ts`](https://github.com/webpack/postcss-loader/main/src/config.d.ts).'
     );
   });
 
   it('should preserve comments inside code blocks', () => {
     const options = {
       source:
-        'https://raw.githubusercontent.com/webpack-contrib/postcss-loader/master/README.md',
+        'https://raw.githubusercontent.com/webpack/postcss-loader/main/README.md',
     };
     const loaderMDData = `
     <!-- some comment that should be dropped -->