TR.html is not the file you want to be changing (possibly that file shouldn't even exist in the github repo? I have no idea how the actual publishing process works though).
So I'm not entirely sure what changes #49 is expecting to make. Possibly changing the "Feedback:" line at the top of the spec to not mention the mailing list. But that would possibly even require code changes to bikeshed? Not sure. It seems like bikeshed just always includes the mailing list there if there is one defined for the spec (and the default templates for the webplatform working group define the mailing list).
So sorry about this, but I'm pretty sure that whatever changes #49 wants to have made should really be made in the upstream webplatform working group bikeshed templates and/or code.
TR.html is not the file you want to be changing (possibly that file shouldn't even exist in the github repo? I have no idea how the actual publishing process works though).
But any changes should be made to the editors draft in the index.bs file (and then possibly run bikeshed to regenerate index.html), to update the index.html file. But even then most of the feedback info is taken from the webplatform working group templates bikeshed provides (such as https://github.com/tabatkins/bikeshed/blob/master/bikeshed/boilerplate/webplatform/status-ED.include).
So I'm not entirely sure what changes #49 is expecting to make. Possibly changing the "Feedback:" line at the top of the spec to not mention the mailing list. But that would possibly even require code changes to bikeshed? Not sure. It seems like bikeshed just always includes the mailing list there if there is one defined for the spec (and the default templates for the webplatform working group define the mailing list).
So sorry about this, but I'm pretty sure that whatever changes #49 wants to have made should really be made in the upstream webplatform working group bikeshed templates and/or code.