docs: added fiddle support for code samples (#26501)

* docs: added fiddle support for code samples in quick start guide and features

* docs: removed excessive fiddle links for not final steps

* docs: added eof newlines to fiddle examples

* docs: reworked fiddle examples to be more self-sufficient

* docs: reworked fiddle examples according to mentions

* docs: changed http to https in the offscreen rendering fiddle

* docs: fix recent documents fiddle to be more consistent

docs/tutorial/offscreen-rendering.md

@@ -34,7 +34,7 @@ To enable this mode GPU acceleration has to be disabled by calling the
 
 ## Usage
 
-``` javascript
+```javascript fiddle='docs/fiddles/features/offscreen-rendering'
 const { app, BrowserWindow } = require('electron')
 
 app.disableHardwareAcceleration()