chore(docs): renamed plugin txt files to md

fixes #3507
chore(docs): cleanup markdown text of readme files
fix(css): markdown code blocks should not should nested borders
chore(cleanup): removed unused javascript file counter.js in thewire

fixes #6933
fix(menus): allow max depth of 20 to prevent losing menu items

fixes #5570
fix(login): also allow login by email in maintenance mode

fixes #6878
Merge pull request #7373 from jdalsem/menu-builder-max-depth

fix(menus): allow max depth of 20 to prevent losing menu items
Merge pull request #7370 from jdalsem/replace-txt-with-md

Replace txt with md
perf(river): only fetch comments if comment_count > 0

fixes #6951
fix(friends): show friends collections menu item in friend context

Not on all pages related to friends the menu item for friends
collections was shown. It now shows more consistently.

fixes: #4810
Merge pull request #7377 from jdalsem/river-responses-perf

perf(river): only fetch comments if comment_count > 0
chore(discussion): cleanup old upgrade action

The action script was moved to a different location, but the
registration was left behind.

fixes: #6932
Merge pull request #7383 from jeabakker/discussions-upgrade-cleanup

chore(discussion): cleanup old upgrade action
fix(views): add apple-touch-icon

Fixes #6176
Merge pull request #7378 from jeabakker/collections-page-menu

fix(friends): show friends collections menu item in friend context
Merge pull request #7388 from PerJensen/homescreen_icon

fix(views): add apple-touch-icon
Merge pull request #7371 from jdalsem/remove-wire-counter-js

chore(cleanup): removed unused javascript file counter.js in thewire
Merge pull request #7374 from jdalsem/email-login-maintenance-mode

fix(login): also allow login by email in maintenance mode