update docs

docs/api/app.md

@@ -533,6 +533,27 @@ You can request the following paths by the name:
 * `logs` Directory for your app's log folder.
 * `pepperFlashSystemPlugin` Full path to the system version of the Pepper Flash plugin.
 
+### `app.getFileIcon(path[, options], callback)`
+
+* `path` String
+* `options` Object (optional)
+  * `size` String
+    * `small` - 16x16
+    * `normal` - 32x32
+    * `large` - 48x48 on _Linux_, 32x32 on _Windows_, unsupported on _macOS_.
+* `callback` Function
+  * `error` Error
+  * `icon` [NativeImage](native-image.md)
+
+Fetches a path's associated icon.
+
+On _Windows_, there a 2 kinds of icons:
+
+- Icons associated with certain file extensions, like `.mp3`, `.png`, etc.
+- Icons inside the file itself, like `.exe`, `.dll`, `.ico`.
+
+On _Linux_ and _macOS_, icons depend on the application associated with file mime type.
+
 ### `app.getFileIcon(path[, options])`
 
 * `path` String

docs/api/breaking-changes.md

@@ -8,29 +8,6 @@ The `FIXME` string is used in code comments to denote things that should be fixe
 
 # Planned Breaking API Changes (5.0)
 
-## `app.getFileIcon(path[, options], callback)`
-
-The `getFileIcon` function on `app` taking a callback is being deprecated in favor of a version returning a Promise.
-
-```js
-const path = 'some/path/to/your/icon'
-// Deprecated
-app.getFileIcon(path, (err, icon) => {
-  if (err) {
-    console.log('oh no an error!', err)
-  } else {
-    console.log(icon)
-  }
-})
-// Replace With
-app.getFileIcon(path)
-  .then(icon => {
-    console.log(icon)
-  }).catch(err => {
-    console.log('oh no an error!', err)
-  })
-```
-
 ## `new BrowserWindow({ webPreferences })`
 
 The following `webPreferences` option default values are deprecated in favor of the new defaults listed below.