Remove tenderapp from MSM site

[renderorange]

The support link on msmhq.com goes to https://msm.tenderapp.com/, which last year had a couple posts for help (and then subsequent frustration after no response).

I think it would be best for msm users if we updated the support link from tenderapp to Github issues, then look into shutting down tenderapp.

A couple reasons for this:

• tenderapp appears to be a paid service.

I'm not sure how this is being paid if it is, but I hope not by an autopayment someone has forgotten about.

• people's questions will have a lot more visibility, both by maintainers and active users watching the repo.

Activity in this project has waxed and waned over the years, but there seems to be a handful of people who've recently expressed interest in continuing the project, at least in the short term. Issues here will be seen, vs unseen in a service no one is watching or being notified about.

If anyone has strong opposition to removing tenderapp in favor of Github issues, please feel free to voice your concerns.

If anyone knows anything about msm's tenderapp subscription, or how to shut it down, any information here is appreciated.

Thanks :)

[endofcake]

Good spotting. #417

[endofcake]

PR merged.