Codemirror Telegram Markdown Mode
Test case that should be supported:
*bold text*
_italic text_
[inline URL](http://www.example.com/)
[inline mention of a user](tg://user?id=123456789)
`inline fixed-width code`
```block_language pre-formatted
fixed-width code block ```
#hash
@username
http://link/to (http link)
https://link/to (https link)
ftp://link/to (ftp link)
tg://user (tg link)