ActivityPub's spec isn't specific in certain areas, so this document describes common usage.
text/plain
is easy to render. Potentially you can go through and try to identify links to make them easily selectable.
text/gemini
is not used by anyone but easy to render and nice for Twitter-style content.
text/html
: I will support:
From section 4.8: img, audio, video, iframe for image/*, audio/*, video/*, and text/html. From section 4.6: a From section 4.5: most of the elements From section 4.4: most of the elements From section 4.3: h1, h2, etc.