[ActionSheet] Update docs to include themers (#5209)

### Context
The docs for ActionSheet haven't been updated since the initial PR.
### The problem
There was no section for theming, color or typography theming.
### The fix
Add sections for both color and typography theming to the README.

components/ActionSheet/README.md

@@ -37,6 +37,8 @@ the screen and displays actions a user can take.
   - [Typical use](#typical-use)
 - [MDCActionSheetController vs. UIAlertControllerStyleActionSheet](#mdcactionsheetcontroller-vs.-uialertcontrollerstyleactionsheet)
 - [Extensions](#extensions)
+  - [Color Theming](#color-theming)
+  - [Typography Theming](#typography-theming)
 - [Accessibility](#accessibility)
   - [Set `-isScrimAccessibilityElement`](#set-`-isscrimaccessibilityelement`)
   - [Set `-scrimAccessibilityLabel`](#set-`-scrimaccessibilitylabel`)
@@ -163,6 +165,91 @@ Material UIAlertController please see the `MDCAlertController` class.
 
 ## Extensions
 
+<!-- Extracted from docs/color-theming.md -->
+
+### Color Theming
+
+You can theme an Action Sheet with your app's color scheme using the ColorThemer extension.
+
+You must first add the Color Themer extension to your project:
+
+```bash
+pod `MaterialComponentsAlpha/ActionSheet+ColorThemer`
+```
+
+<!--<div class="material-code-render" markdown="1">-->
+#### Swift
+```swift
+// Step 1: Import the ColorThemer extension
+import MaterialComponentsAlpha.MaterialActionSheet_ColorThemer
+
+// Step 2: Create or get a color scheme
+let colorScheme = MDCSemanticColorScheme()
+
+// Step 3: Apply the color scheme to your component
+let actionSheet = MDCActionSheetController()
+MDCActionSheetColorThemer.applySemanticColorScheme(colorScheme, to: actionSheet)
+```
+
+#### Objective-C
+
+```objc
+// Step 1: Import the ColorThemer extension
+#import "MaterialActionSheet+ColorThemer.h"
+
+// Step 2: Create or get a color scheme
+id<MDCColorScheming> colorScheme = [[MDCSematnicColorScheme alloc] init];
+
+// Step 3: Apply the color scheme to your component
+MDCActionSheetController *actionSheet = [[MDCActionSheetController alloc] init];
+[MDCActionSheetColorThemer applySemanticColorScheme:self.colorScheme
+                            toActionSheetController:actionSheet];
+```
+<!--</div>-->
+
+<!-- Extracted from docs/typography-theming.md -->
+
+### Typography Theming
+
+You can theme an Action Sheet with your app's typography scheme using the TypographyThemer extension.
+
+You must first add the Typography Themer extension to your project:
+
+```bash
+pod `MaterialComponentsAlpha/ActionSheet+TypographyThemer`
+```
+
+<!--<div class="material-code-render" markdown="1">-->
+#### Swift
+```swift
+// Step 1: Import the ColorThemer extension
+import MaterialComponentsAlpha.MaterialActionSheet_TypographyThemer
+
+// Step 2: Create or get a color scheme
+let typographyScheme = MDCTypographyScheme()
+
+// Step 3: Apply the color scheme to your component
+let actionSheet = MDCActionSheetController()
+MDCActionSheetTypographyThemer.applyTypographyScheme(typographyScheme, to: actionSheet)
+```
+
+#### Objective-C
+
+```objc
+// Step 1: Import the ColorThemer extension
+#import "MaterialActionSheet+TypographyThemer.h"
+
+// Step 2: Create or get a color scheme
+id<MDCTypographyScheming> typographyScheme = [[MDCTypographyScheme alloc] init];
+
+// Step 3: Apply the color scheme to your component
+MDCActionSheetController *actionSheet = [[MDCActionSheetController alloc] init];
+[MDCActionSheetTypographyThemer applyTypographyScheme:self.typographyScheme
+                              toActionSheetController:actionSheet];
+```
+<!--</div>-->
+
+
 <!-- Extracted from docs/accessibility.md -->
 
 ## Accessibility

components/ActionSheet/docs/README.md

@@ -55,4 +55,7 @@ Material UIAlertController please see the `MDCAlertController` class.
 
 ## Extensions
 
+- [Color Theming](color-theming.md)
+- [Typography Theming](typography-theming.md)
+
 - [Accessibility](accessibility.md)

components/ActionSheet/docs/color-theming.md

@@ -0,0 +1,39 @@
+### Color Theming
+
+You can theme an Action Sheet with your app's color scheme using the ColorThemer extension.
+
+You must first add the Color Themer extension to your project:
+
+```bash
+pod `MaterialComponentsAlpha/ActionSheet+ColorThemer`
+```
+
+<!--<div class="material-code-render" markdown="1">-->
+#### Swift
+```swift
+// Step 1: Import the ColorThemer extension
+import MaterialComponentsAlpha.MaterialActionSheet_ColorThemer
+
+// Step 2: Create or get a color scheme
+let colorScheme = MDCSemanticColorScheme()
+
+// Step 3: Apply the color scheme to your component
+let actionSheet = MDCActionSheetController()
+MDCActionSheetColorThemer.applySemanticColorScheme(colorScheme, to: actionSheet)
+```
+
+#### Objective-C
+
+```objc
+// Step 1: Import the ColorThemer extension
+#import "MaterialActionSheet+ColorThemer.h"
+
+// Step 2: Create or get a color scheme
+id<MDCColorScheming> colorScheme = [[MDCSematnicColorScheme alloc] init];
+
+// Step 3: Apply the color scheme to your component
+MDCActionSheetController *actionSheet = [[MDCActionSheetController alloc] init];
+[MDCActionSheetColorThemer applySemanticColorScheme:self.colorScheme
+                            toActionSheetController:actionSheet];
+```
+<!--</div>-->

components/ActionSheet/docs/typography-theming.md

@@ -0,0 +1,39 @@
+### Typography Theming
+
+You can theme an Action Sheet with your app's typography scheme using the TypographyThemer extension.
+
+You must first add the Typography Themer extension to your project:
+
+```bash
+pod `MaterialComponentsAlpha/ActionSheet+TypographyThemer`
+```
+
+<!--<div class="material-code-render" markdown="1">-->
+#### Swift
+```swift
+// Step 1: Import the ColorThemer extension
+import MaterialComponentsAlpha.MaterialActionSheet_TypographyThemer
+
+// Step 2: Create or get a color scheme
+let typographyScheme = MDCTypographyScheme()
+
+// Step 3: Apply the color scheme to your component
+let actionSheet = MDCActionSheetController()
+MDCActionSheetTypographyThemer.applyTypographyScheme(typographyScheme, to: actionSheet)
+```
+
+#### Objective-C
+
+```objc
+// Step 1: Import the ColorThemer extension
+#import "MaterialActionSheet+TypographyThemer.h"
+
+// Step 2: Create or get a color scheme
+id<MDCTypographyScheming> typographyScheme = [[MDCTypographyScheme alloc] init];
+
+// Step 3: Apply the color scheme to your component
+MDCActionSheetController *actionSheet = [[MDCActionSheetController alloc] init];
+[MDCActionSheetTypographyThemer applyTypographyScheme:self.typographyScheme
+                              toActionSheetController:actionSheet];
+```
+<!--</div>-->