chore (script): add wakapi backup script

scripts/backup_wakapi_db.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+
+WAKAPI_CONTAINER="wakapi"
+BACKUP_DIRECTORY="$HOME/backups/wakapi/"
+
+echo "INFO Creating compressed backup of ${WAKAPI_CONTAINER} database."
+
+rm $HOME/backups/wakapi/*
+
+sleep 1
+
+docker exec $WAKAPI_CONTAINER \
+	bash -c "sqlite3 /data/wakapi.db '.backup /tmp/backup.sq3' && gzip -c /tmp/backup.sq3" >"${BACKUP_DIRECTORY}$(date +%Y%m%d).sq3.gz"
+
+STATUS=$?
+if [ $STATUS -eq 0 ]; then
+	$RCHAT_NOTIFIER "backups" "success" \
+		"Created backup of ${WAKAPI_CONTAINER} SQLite database on VPS."
+else
+	$RCHAT_NOTIFIER "backups" "error" \
+		"Failed to create backup of ${WAKAPI_CONTAINER} SQLite database: exit code $STATUS."
+fi