Design a GitHub template to allow people to submit requests of adding their models into GPlately

[michaelchin]

Design a GitHub template to allow people to request adding their models into GPlately so that we can keep records. The records could be useful when we need to check the history. If people are reluctant to use the template, I will do it for them. Mostly, it is I who need to keep the records.

This is part of the plate model management task.

[michaelchin]

This can wait. I don't have time to do it right now. Put it on ice.