New year, new copyright, new expected unknown issues with various files
that won't be covered by the script and/or will be but shouldn't change.
I'll do the details on Jan 1, but would appreciate this being
preapproved so I can actually get it merged by then.
CHANGELOG_BEGIN
CHANGELOG_END
Rely on zsh features to simplify profile_zsh.sh file.
- Remove `DADE_REPO_ROOT` as it is not needed anywhere, `dade-assist` redefines
it already.
- `${0:A:h}` gives the absolute path of the folder *this* file resides in, no
need for `cd`, `dirname`, and `pwd` combo.
- Use simple process redirection (`<`), as it is more robust than the one in
bash, and works better than `<<<`
