The crossplane/docs repository uses the vale tool to lint prose. It's a little
overzealous sometimes, but overall helpful, and currently complains about a ton
of issues in our help text.

Fix as many issues as possible. Use a special spell check (to be introduced in
the docs repo) to avoid complaints about lower-case `crossplane`, since it's the
command name.

The remaining issues we can't fix are:

- The abbreviation `config` in the `crossplane config` command.
- The abbreviation `k8s` in the flag help for `crossplane dependency add`.
- The abbreviation `admin` in `cluster-admin` in the help for `crossplane
  project run`.

Signed-off-by: Adam Wolfe Gordon <awg@upbound.io>
(cherry picked from commit 21e2451)

Fix a few spelling/grammar/typo issues caught by CodeRabbit, and close tables if
the last line of help is a table row.

Signed-off-by: Adam Wolfe Gordon <awg@upbound.io>
(cherry picked from commit 51de2c5)

We have a few commands whose basic (non-detail) help causes vale
errors. Specifically:

* `config` is a forbidden word, so `crossplane config` triggers a warning.
* `k8s` is forbidden confuses a few checks, and we use it in the help for
  `crossplane dependency add`.
* `admin` is a forbidden word, but it's necessary to name the `cluster-admin`
  role in the help for `crossplane project run`.

Add the ability to tag commands with `novale:"..."`, causing specific vale rules
to be ignored for that command's section of the help. Introduce these on the
commands named above.

Signed-off-by: Adam Wolfe Gordon <awg@upbound.io>
(cherry picked from commit 7b0191f)

After building the CLI, check out the docs repo, use our freshly built binary to
generate the CLI reference documentation, and validate it using the docs repo's
vale config. This will ensure our generated docs always pass CI when put up for
review in the docs repo.

Fixes #32

Signed-off-by: Adam Wolfe Gordon <awg@upbound.io>
(cherry picked from commit aa6d376)

Signed-off-by: Adam Wolfe Gordon <awg@upbound.io>
(cherry picked from commit 66bd530)