feat!: replace dgeni/gulp with TypeDoc for README generation

Replace the legacy dgeni/gulp documentation pipeline with TypeDoc
and typedoc-plugin-markdown. Generates plugin README files with
extracted @Plugin() decorator metadata. Register custom JSDoc tags
used by plugin source files.

docs/plugins/sign-in-with-apple/README.md

@@ -1,5 +1,7 @@
-# ASAuthorizationAppleIDRequest
-c cordova plugin add cordova-plugin-sign-in-with-apple
+# Sign In With Apple
+
+```
+$ ionic cordova plugin add cordova-plugin-sign-in-with-apple
 $ npm install @awesome-cordova-plugins/sign-in-with-apple
 ```
 
@@ -17,6 +19,4 @@ Source:* https://developer.apple.com/sign-in-with-apple/
 ## Supported platforms
 
 - iOS
-  
-