Add **note** to alert migration note

content/docs/alerting/rules.md

@@ -56,7 +56,7 @@ clause.
 
 Label values in the `WITH` clause cannot be templated.
 
-Old alerting rules can be converted to the new syntax using [this script](https://gist.github.com/xbglowx/d798da98ff9937e33862b285d0121bde#gistcomment-1752515).
+NOTE **Note:** Old alerting rules can be converted to the new syntax using [this script](https://gist.github.com/xbglowx/d798da98ff9937e33862b285d0121bde#gistcomment-1752515).
 
 
 #### Templating