I sometimes have the situation that I want to create empty lines but
they contain either whitespace from keeping the indentation and/or the
comment string (`o` on a comment line). My current workflow is to either
delete it and recreate it properly (e.g. from the 'other side' i.e. a
non-comment line) or clear it with `cc`. Both ways are a bit awkward.
Add a mapping that clears a line but stays in normal mode.
Also remove the `<leader>d` mapping that deletes and puts the content
into the system clipboard as I rarely use this one.