Support for embedding YouTube Video.

[gajjug004]

User should be able to embed YouTube video. And able to play video on their wiki page.

[simonlpaige]

The YouTube embed feature request (#619) would benefit from clarifying the expected scope. Frappe Wiki uses Markdown for content rendering via Frappe's framework. The simplest implementation would be to extend the existing Markdown parsing to convert YouTube URLs (both youtube.com/watch?v= and youtu.be/ shortlinks) into embedded <iframe> elements, similar to how GitHub Flavored Markdown handles video embeds.

A concrete use case: documentation pages often need to embed tutorial videos inline with text, rather than just linking out. For example, an ERPNext setup guide could show a 2-minute walkthrough video between configuration steps. The current workaround is to use raw HTML <iframe> tags in the Markdown source, but this is blocked if the wiki has HTML sanitization enabled (which is the default in Frappe for security).

If this is implemented, it should also respect the wiki's existing permission and revision history systems - embedded video URLs should be tracked in page versions and require approval if change control is enabled. Additionally, consider whether the embed should support start/end timestamps via URL parameters (?t=60s), as that's a common need for pointing to specific sections of longer videos.