chore(readme): github glob example

[dimateos]

I tried the "Github final path as title for blobs" example because it seemed pretty useful... well it was outdated?

I updated the current DOM id for the filename! This is my full rule which adds the repo name too, I can commit it if you prefer:

• Detection: RegExp
• URL fragment: github[.]com/([A-Za-z0-9-]+)/([A-Za-z0-9-]+)/blob/
• Title: {#file-name-id-wide} /$2
• URL matcher: github[.]com/([A-Za-z0-9-]+)/([A-Za-z0-9-]+)/blob/

❓:: I also have one for github[.]com/search pages if you are interested in another example