Add terminal mode support

[vais]

Currently the plugin does not work in vim's built-in :terminal buffers. These changes make it so it does.

[vais]

Not sure why this didn't work for you before, but the direct way works fine for me now in vim 9.1 (and this fixes an issue that the current implementation causes in terminal mode)

[benknoble]

If I were the author or maintainer, I would find this change a lot easier to review if your cover letter (PR description) or commit message explained what problem exists in terminal buffers and how these changes resolve it.

[vais]

The main problem is the absence of mappings for terminal mode, i.e. the plugin simply does noting in terminal mode.

The secondary problem (once the mappings for terminal mode are created), is that the above code for clearing the -- RESIZE -- status message dumps the text :echo into the terminal buffer instead of doing what it was intending to do.

Hope this helps clarify the issue ❤️

[sedm0784]

Thank you for this! (And sorry for the slow response. I don't log into GitHub all that frequently as you can probably tell from my commit graph.)

I'm not going to merge it in as is, because I'd like the plugin to continue working in all the versions/contexts in which it worked before, and the removal of the feedkeys() will break this. When I get a chance though, I'll make a tweak to the feedkeys arguments while in terminal mode so that they are not simply entered into whatever's running in the terminal and instead sent to Vim correctly.