Provide a config option to use the primary clipboard

[hashworks]

When one uses a clipboard manager wl-copy --clear doesn't always work correctly. Thus, one gathers a lot of secrets in the clipboard manager. However, the primary clipboard normally isn't read by the clipboard manager, making it an optimal target for secrets.

[hashworks]

Fixed the format issue with shfmt -w -s -i 2 -bn -ci -sr tessen.

[hashworks]

@ayushnix When do you plan to release 2.3.0? :)

[ayushnix]

forgot about pending PRs on this repo 😅, thanks for reminding me

I'll review the pending PRs and merge them this weekend.