[Plugin Submission Form] Add a "I have tested my plugin using the Plugin Check plugin" checkbox

[mrfoxtalbot]

Once the ​Plugin Check plugin (PCP) is released, we should add a checkbox to the plugin submission form requiring plugin authors to confirm that they have self-checked their own plugins using the PCP.

The content of the check box could be something like this:

□ I have checked my plugin using the ​Plugin Check plugin and fixed all issues and errors. (If you have done this and think you are seeing a false positive, please ​open an issue)

If their plugin has not passed the check but they think this is a false positive, I think it makes sense to provide an alternative route but I am worried it might get abused. What do you think?

Down the road, I would like to have a system to check plugins automatically as part of the submissions process but, for now, this is a good first step.

[mrfoxtalbot]

Now that the ​plugin check has been released, we are ready to add this check.

Our hope is that, in the near future, plugins will be automatically checked as part of the submission process but, for now, adding this check would raise awareness about the plugin and hopefully reduce the number of "broken" plugins being submitted for review.