Improve getting started column (#7676)

* Adjust footer of getting started column

- Improved style
- Moved hotkeys, about this instance and logout to footer
- Removed FAQ, User Guide, Apps links
- Use hamburger icon for the column

* Add edit profile action button to profile and more to dropdown

* Add "Trending now" to getting started column

* Add preferences/security links on mobile layout

app/javascript/mastodon/locales/en.json

@@ -165,7 +165,7 @@
   "navigation_bar.favourites": "Favourites",
   "navigation_bar.follow_requests": "Follow requests",
   "navigation_bar.info": "About this instance",
-  "navigation_bar.keyboard_shortcuts": "Keyboard shortcuts",
+  "navigation_bar.keyboard_shortcuts": "Hotkeys",
   "navigation_bar.lists": "Lists",
   "navigation_bar.logout": "Logout",
   "navigation_bar.mutes": "Muted users",