Add server status page and a badge in AppBar (#182)

* WIP: Add server status and running process indicators

* Finish ServerStatusPage and ServerRunningProcess

* fix typos, add running process info to the server status page

* Remove ServerRunningProcess and integrate it into ServerStatusBadge

* remove divider in menu

* display time as started X minutes ago

* add documentation; clearly state what new components are; update readme

* change wording a bit, cross-link with docs/README.md

* use returned HTML

* Finish ServerStatus page and badges

* Fix types

* cleanup

* remove some code

* adjust config load

README.md

@@ -101,6 +101,7 @@ The following changes are already implemented:
 * 🖼️ [Add rooms' avatars](https://github.com/etkecc/synapse-admin/pull/158)
 * 🤖 [User Badges](https://github.com/etkecc/synapse-admin/pull/160)
 * 🔑 [Allow prefilling any fields on the login form via GET params](https://github.com/etkecc/synapse-admin/pull/181)
+* _(for [etke.cc](https://etke.cc) customers only)_ [Server Status indicator and page](https://github.com/etkecc/synapse-admin/pull/182)
 
 
 _the list will be updated as new changes are added_