fix headline in docs

docs/20_Features.md

@@ -34,7 +34,7 @@ Limited support:
 * delete backups by rules to keep a count of hourly, daily, weekly, mothly, yearly backups
 * several backup targets (currently supported protocols: sftp:// https:// and file://)
 
-# Control simoultanous backups #
+# Limit simoultanous backups #
 
 As an optional feature you can control the count simultanous written backups.
 This requires additional effort next to the client installation.