Update README.MD

Navicat/navicat121_premium_cs.dmg/README.MD

@@ -1 +1,7 @@
-#
+# Download
+[http://download.navicat.com/download/navicat121_premium_cs.dmg](http://download.navicat.com/download/navicat121_premium_cs.dmg)
+
+# Backup
+```
+bash <(curl -sSL "https://raw.githubusercontent.com/MoeClub/Note/master/Navicat/navicat121_premium_cs.dmg/download.sh")
+```