Add documentation for Rule.use as a function (#2694)

Author: bew

src/content/configuration/module.md

@@ -308,12 +308,25 @@ module.exports = {
 
 ## `Rule.use`
 
-A list of [UseEntries](#useentry) which are applied to modules. Each entry specifies a loader to be used.
+`[UseEntry] | function`
+
+`Rule.use` can be an array of [UseEntry](#useentry) which are applied to modules. Each entry specifies a loader to be used.
 
 Passing a string (i.e. `use: [ 'style-loader' ]`) is a shortcut to the loader property (i.e. `use: [ { loader: 'style-loader '} ]`).
 
 Loaders can be chained by passing multiple loaders, which will be applied from right to left (last to first configured).
 
+`Rule.use` can be a function which receives the object argument describing the module being loaded, and must return an array of `UseEntry`.
+
+The object parameter has the following fields:
+
+- `compiler`: The current webpack compiler (can be undefined)
+- `issuer`: The path to the module that is importing the module being loaded
+- `realResource`: Always the path to the module being loaded
+- `resource`: The path to the module being loaded, it is usually equal to `realResource` except when the resource name is overwritten via `!=!` in request string
+
+The same shortcut as an array can be used for the return value (i.e. `use: [ 'style-loader' ]`).
+
 __webpack.config.js__
 
 ```javascript