Testing Team announcement + state of postmarketOS

• Announce the testing team
• Add a page about the current state of the project, so people don't have wrong expectations. Mention the testing team there as direct way for people to improve quality.

I plan to merge this on Sunday.

Closes: pmaports#1824

config/wiki.py

@@ -48,6 +48,7 @@ redirects = {
     "recoveryzip": "Android_Recovery_Zip_Installation",
     "renamed": "Renamed_Devices",
     "ssh": "SSH",
+    "testing": "Testing_Team",
     "troubleshooting": "Troubleshooting",
     "uipkg": "UI_specific_package",
     "upgrade": "Upgrade_release",