Implement ":delm[arks]" Vim command to delete marks

[austindd]

Right now, I don't know of a way to delete a Vim mark in Zed. Setting marks and jumping to them works pretty well. But the ":delm[arks]" command doesn't seem to be implemented yet. Is there a workaround for this?

I know I can always just overwrite the marks I want to use, but it just feels very unhygienic to leave them there forever.

Also, I believe the official Vim behavior for marks is to delete the mark associated with a line if that line is deleted from the buffer. This doesn't seem to work in Zed. Instead, Zed just continues to use the original line number, regardless of any changes to the file. I would like to have that work correctly in Zed.