I ran [proselint](https://github.com/amperser/proselint) (recommended by
cURL author [Daniel
Stenberg](https://daniel.haxx.se/blog/2022/09/22/taking-curl-documentation-quality-up-one-more-notch/))
against all the `.md` files in the codebase to see if I could fix some
easy typos.

The tool is noisier than I would like and picking up the overrides to
the default config in a `.proselintrc.json` was much harder than I
expected.

There's many other small nits [1] that I believe are best left to your
docs czar whenever they want to consider incorporating a tool like this
into big releases or CI, but these seemed like small wins for now to
open a conversation about a tool like proselint.

---

[1]: Such nits include
- incosistent 1 or 2 spaces
- "color" vs "colour"
- ab/use of `very` 
- awkward or superfluous phrasing.

Release Notes:

- N/A

Signed-off-by: mrg <miguelraz@ciencias.unam.mx>