Limit the maximum number of avatars shown for other user read markers and collapsed state events
For state events \

For read markers \

Restore part of the contents previously introduced by
cc21f8cca9 which was partially
lost, probably due to an extra '>' outside the tags
which confused the translation system.
Credits for the text, see the original commit (Carl Schwan).
Unread count is deprecated and notification count should be used in all cases. As such remove unreadCount and use notification count in all places it was being used.
Fixesnetwork/neochat#76 \
BUG: 466515
Update README.md ensuring that info is up to date.
The following has been changed:
- Updated about info (intro, features)
- Reference KDE standard docs for building, MRs, etc
This move the finding of links and the creation of a `linkpreviewer` into c++.
- The links are now extracted from the text in `texthandler`
- The `messageeventmodel` now creates and stores `linkpreviewers` for events that have links in the current room.
Two new model roles have been created to let a text delegate know when the link preview should be shown (`showLinkPreview`) and pass the link previewer (`linkPreviewer`). Empty link previewer are returned where link don't exist so the qml doesn't have to have checks for whether the parameters are undefined.
Further improvements to the handling of `mediaInfo` in `messageeventmodel`.
`blurhash` and `thumbnailInfo` are now replaced with a single `tempInfo` object that contains a single temp source. The priority is thumbnail > `blurhash` > empty if none exist.
Fixesnetwork/neochat#235