Many of the tmux plugins had not been updated in some time. This PR:
- Updates all of them to the latest version. This is notable because `tmux 3.0`
has come out recently, and some of them have compatibility fixes for the new
version (e.g., `vim-tmux-navigator`), as well as general performance
improvements and bugfixes for many of them.
- Uses `fetchFromGitHub`, which is both more performant and hashed mirror friendly.
- Adds the standard `version = "unstable-YYYY-MM-DD"`, which makes it easy to
determine at a glance how old/unmaintained some of these are.
- Adds the standard `pname` for overlay friendliness