Update CONTRIBUTING.md (#55)

Added documentation on Adding new Messages

Closes #52

CONTRIBUTING.md

@@ -6,4 +6,46 @@
   - Changes that are not within the scope of the description will result in the entire PR being rejected
 - No updates should be made directly to the automatically generated ServiceNow folders. Updates to these files should be done via the [Regular method](README.md#manually) described on the readme.
 - Low effort/spam Pull Requests will be marked as spam accordingly.
-- Filenames should not have special characters that are not allowed on normal file systems (eg. do not put ! in the file name).
+- Filenames should not have special characters that are not allowed on normal file systems (eg. do not put ! in the file name).
+
+
+## Messages
+
+To contribute new messages for when points are awarded or milestones are reached:
+1. Fork this repo and import it into your instance
+2. In your instance navigate to `Points Thing > Messages`
+3. Add an entry
+4. In Studio, commit your changes to source control
+5. Submit a pull request to the ServiceNowDevProgram/Points-Thing main branch
+
+### To create a new message
+
+There are three fields to fill in, Message, Point Trigger, and Send to milestone channel.
+
+#### Message
+
+In the Message field create the string that is the message you want to be sent followed by a semicolon. 
+There are placeholders available for system generated values:
+
+- `user`: the @user name that recieved the points
+- `points`: the new number of points that the user has (90 day running total)
+- 'total`: the actual all time total number of points the user has
+
+An example of a good message would be:
+`'Congrats ' + user + ' you now have ' + points + ' points';`
+
+Note: Any message that is NOT sent to the milestone channel will have `'(' + total + ' total)'` automatically appended to it.
+
+You can also use emojis in your message by including them with the standard :emojiName: notation that slack uses. 
+
+
+#### Point Trigger
+
+This is an optional field. If filled in, the message will only trigger at this number of lifetime total points.
+If blank it will trigger for any number of points that does not have a specific trigger (i.e. if there is a special message for 100 points, that message will trigger and not the blank one).
+If there are multiple messages that have the same trigger value (including blank) the message that will trigger will be randomly chosen.
+
+#### Send to milestone channel
+
+If this is selected than the message will be sent to the defined Milestone channel in addition to the standard reply. This will also suppress the `'(' + total + ' total)'` that gets appended to most messages.
+