Added snapper notes to the knowledge base

knowledge base/snapper.md

@@ -0,0 +1,31 @@
+# Snapper
+
+## TL;DR
+
+```shell
+# list existing configurations
+snapper list-config
+
+# list existing snapshots
+snapper list
+
+# create a manual standalone snapshot
+snapper --config root create --type single --description "manual checkpoint" --userdata "important=yes" --read-only
+
+# rollback to snapshot 0
+snapper rollback 0
+
+# delete one or more snapshots
+snapper delete 5
+snapper delete --sync {7..9}
+
+# compare 2 snapshots
+snapper status 0..6
+snapper diff 6..21
+```
+
+## Further readings
+
+- [Arch Wiki]
+
+[arch wiki]: https://wiki.archlinux.org/title/snapper