Close#1881
More specifically:
- Change mention of app developer tutorial in README to instead
link to developer portal.
- Add a flexbox grid at the top of /developing/ for quick access
icons to next steps, to make it feel more like a "developer
portal" (cc: @jadeqwang), supported by `docs/extra.css`
While I was at it:
- Move the documentation explaining the vague overall design goals
of `vagrant-spk` from `docs/vagrant-spk/index.md` into the existing
file, `docs/vagrant-spk/customizing.md` which allowed me to delete
`docs/vagrant-spk/index.md` entirely.
- Adjust the packaging tutorial to say that some parts might be slow
due to download times.
- Drastically improve (in my opinion) the amount of information, and
its contextualization, within the Developer Portal. Up until now,
Cap'n Proto was not even mentioned once.
- Update commented-out TODO items to indicate that some docs have now
been written.
Note that I did take some liberties with the document; the authoritative
source of the original design is the GitHub wiki history.
I think for the parts of the design that are already obviated, it is
sensible to remove them, so I did.
This largely links to existing documents, rather than copies them wholesale
into docs/. Copying them into docs/ is a goal for the very near future.
This also changes the default them to one where the navigation is not
constantly visible at the top for non-wide screens (aka mobile).