Code block handling

[tezlm]

Describe the problem

• showing line numbers (with user-select: none) would be nice
• markdown fenced code blocks don't seem to work
• there's no way to change the code block's language in the rich text editor
• the editor uses enter to send + tab as navigation (instead of a literal tab) while in a code block

Describe the solution you'd like

add these things

Alternatives considered

No response

Additional context

No response

[williamkray]

not sure if it's worth it, but this issue could effectively be expanded to a feature request to "support multi-line markdown" with details about how to render codeblocks, as the current markdown implementation is limited only to in-line markdown formatting.

[ashkitten]

i run into this deficiency on a regular basis and frustratingly have to go into element to send messages

[yretenai]

Additional broken markdown features: Block quotes (> ), lists, headings. These features are supported by the WYSIWYG but markdown is not processed.

[K900]

Pretty sure this regressed in 3.1.0.

[ajbura]

Pretty sure this regressed in 3.1.0.

@K900 fix #1524 in 3.2.0. Let us know if there is still any issue?