Update exempt labels config for stale bot.

.github/stale.yml

@@ -5,11 +5,51 @@ daysUntilStale: 28
 daysUntilClose: 14
 # Issues with these labels will never be considered stale
 exemptLabels:
-    - 1. developing
+    - 1. to develop
     - 2. to review
     - 3. to release
+    - 4. to test
+    - accessibility
+    - backport-request
+    - bug
+    - design
     - enhancement
+    - epic
+    - discussion
+    - documentation
     - overview
+    - good first issue
+    - feature-request
+    - feature: :arrows_counterclockwise: sync engine
+    - feature: :busts_in_silhouette: sharing
+    - feature: :cloud: system tray
+    - feature: :gear: settings
+    - feature: :inbox_tray: install and update
+    - feature: :key: authentication
+    - feature: :lock: end to end encryption
+    - feature: :memo: versions
+    - feature: :minidisc: external storage
+    - feature: :minidisc: virtual drive
+    - help wanted
+    - high
+    - integration
+    - low
+    - medium
+    - needs info
+    - os: :apple: macOS
+    - os: :door: Windows
+    - os: :penguin: Linux
+    - os: :smiling_imp: FreeBSD
+    - overview
+    - package: appimage
+    - package: debian
+    - package: snap
+    - papercut
+    - regression
+    - security
+    - server
+    - spec
+    - technical debt
 # Label to use when marking an issue as stale
 staleLabel: stale
 # Comment to post when marking an issue as stale. Set to `false` to disable