update docs

docs/40_Usage/10_Backup.md

+```
+# ./backup.sh -?
+
+  ___ ___ ___ ___         _______            __
+ |   |   Y   |   |       |   _   .---.-.----|  |--.--.--.-----.
+ |.  |.      |.  |       |.  1   |  _  |  __|    <|  |  |  _  |
+ |.  |. \_/  |.  |___    |.  _   |___._|____|__|__|_____|   __|
+ |:  |:  |   |:  1   |   |:  1    \                     |__|
+ |::.|::.|:. |::.. . |   |::.. .  /
+ `---`--- ---`-------'   `-------'
+
+_______________________________________________________________________________  ___  __   _
+
+Param: show help
+
+START A BACKUP
+
+This script starts 
+  - the database backups and creates dumps locally
+  - the file backup (using restic or duplicity)
+
+SYNTAX:
+
+    backup.sh [OPTIONS]
+
+    default: no parameter:
+
+OPTIONS:
+
+    -d, --dryrun  just show infos, do not start a backup
+    -h, --help    Show this help
+
+    The following parameters force the backup type (if using duplicity):
+    -a, --auto    force auto 
+    -o, --older   duplicity type=auto: repeat full backup if last full 
+                  backup is older than ... like "1M" for 1 month
+    -f, --full    force full backup (if supported)
+    -i, --inc     force incrmenental backup
+
+```
+