chore: replace old urls

src/content/concepts/hot-module-replacement.mdx

@@ -44,7 +44,7 @@ The compiler ensures that module IDs and chunk IDs are consistent between these
 
 ### In a Module
 
-HMR is an opt-in feature that only affects modules containing HMR code. One example would be patching styling through the [`style-loader`](https://github.com/webpack-contrib/style-loader). In order for patching to work, the `style-loader` implements the HMR interface; when it receives an update through HMR, it replaces the old styles with the new ones.
+HMR is an opt-in feature that only affects modules containing HMR code. One example would be patching styling through the [`style-loader`](https://github.com/webpack/style-loader). In order for patching to work, the `style-loader` implements the HMR interface; when it receives an update through HMR, it replaces the old styles with the new ones.
 
 Similarly, when implementing the HMR interface in a module, you can describe what should happen when the module is updated. However, in most cases, it's not mandatory to write HMR code in every module. If a module has no HMR handlers, the update bubbles up. This means that a single handler can update a complete module tree. If a single module from the tree is updated, the entire set of dependencies is reloaded.
 

src/content/contribute/writing-a-loader.mdx

@@ -139,7 +139,7 @@ Make sure the loader does not retain state between module transformations. Each
 
 ### Loader Utilities
 
-Take advantage of the [`loader-utils`](https://github.com/webpack/loader-utils) package which provides a variety of useful tools. Along with `loader-utils`, the [`schema-utils`](https://github.com/webpack-contrib/schema-utils) package should be used for consistent JSON Schema based validation of loader options. Here's a brief example that utilizes both:
+Take advantage of the [`loader-utils`](https://github.com/webpack/loader-utils) package which provides a variety of useful tools. Along with `loader-utils`, the [`schema-utils`](https://github.com/webpack/schema-utils) package should be used for consistent JSON Schema based validation of loader options. Here's a brief example that utilizes both:
 
 **loader.js**
 

src/content/migrate/3.mdx

@@ -267,7 +267,7 @@ Thus make sure to remove the plugin from your configuration:
 
 ## ExtractTextWebpackPlugin - breaking change
 
-[ExtractTextPlugin](https://github.com/webpack-contrib/extract-text-webpack-plugin) requires version 2 to work with webpack 2.
+[ExtractTextPlugin](https://github.com/webpack/extract-text-webpack-plugin) requires version 2 to work with webpack 2.
 
 `npm install --save-dev extract-text-webpack-plugin`