[UI] Post style menu (Plain text, Markdown, HTML)

[SadmL]

Problem I have

As GoToSocial user i've set my posts to use Markdown by default, but sometimes I want to just write plain text with

• Thing 1
• Thing 2
  👆 but it's looks like in Github, I wanna 👇 , but without code block

- Thing 1
- Thing 2

Changing post style possible only via GtS admin UI, that is slightly inconvenient

Solution I'd like

Like Moshidon app (screenshot)

UI with icon from Moshidon app (4th from bottom left)

Alternatives considered

No response

Other

#363 may be related

[SadmL]

#842 may be related