I believe I had the problem in the past that the completion wouldn't
automatically select the first entry but simply display the menu. Thus
it would simply insert a new line when pressing return to accept it.
Unfortunately I didn't commit it back then and I can't reproduce it now.
But it doesn't not hurt so I commit it to be safe.
CoC disables backup files due to a problem with a typescript
language-server (it becoming slow when the backup file is written,
triggering a `structureChanged`). But:
1. I want backup files
2. I do not use that language server
3. If I would:
1. I could disable backup files in a filetype plugin
2. The linked issue is from 2019 - no idea if this is still
present today
4. I don't think this issue is even a thing with a `&backupdir` that
does not include relative directories (which is the case for me)
So remove the lines disabling backups and go back to vim's defaults:
`nobackup` and `writebackup`.
Link: https://github.com/neoclide/coc.nvim/issues/649
- CheckBackspace needs to be used instead of <SID>CheckBackspace
- Comment out clashing/obtrusive leader/space mappings
- Change classobj mappings to use `o` as they were clashing with the
comment textobj.
- Simulate the default statusline with the help of 'statusline'.
Otherwise it would be empty/just containing coc elements.
