Removing we are on pause from the submission template

[lwasser]

This PR does a few things

1. it remove the "we are on pause" language so we can begin accepting submissions again
2. It adds a date accepted to the yaml to allow us to better track acceptance of packages. this will be useful for database purpose and website publishing
3. requests a list of all maintainers of the package. i realized most packages have more than 1 and having all of them in our database is useful for many reasons. also we would invite them all to slack and promote them all on twitter.

NOTE: there is a quirk where the markdown isn't rendering the way that we want it to as a list without bullets but the template itself is fine - i've checked it in several text editors.

in the FUTURE could be worth considering a better template like this: https://docs.github.com/en/communities/using-templates-to-encourage-useful-issues-and-pull-requests/configuring-issue-templates-for-your-repository but that might be at the risk of losing parsability like what ROS uses

[lwasser]

@NickleDave or @xmnlab can one of you please have a look at this and approve or comment? 🙌

[xmnlab]

LGTM! thanks @lwasser