CampTix Tools Notify - Add Placeholder or Tooltip to Purchase Date Field

Imported from https://meta.trac.wordpress.org/ticket/4056
Created by @megabyterose:

It's unclear what type of date or datetime format this input takes. I believe it's run through strtotime(), but there's no indication for the user to know how they should format the date.

https://i.ibb.co/Wcb35y8/camptix-purchase-date-needs-example.png

Comment by slackbot:

This ticket was mentioned in Slack in #meta-wordcamp by iandunn. View the logs.

Comment by @iandunn:

• Keywords set to Needs Patch Good First Bug
• Status set to assigned

+1.

There's some discussion about implementation details in the Slack link above.

Comment by slackbot:

This ticket was mentioned in Slack in #meta-wordcamp by donmhico. View the logs.

Comment by @donmhico:

• fixed-ss.png added

Since the files affected are in camptix plugin. I've created a PR in CampTix's GitHub. See - Automattic/camptix#242

Comment by slackbot:

This ticket was mentioned in Slack in #meta-wordcamp by ryelle. View the logs.