**what is the change?:**
This just updated the error codes on the docs.
For my future self, recording the steps it took to get here:
- On master, run `npm run build -- --extract-errors`
- Create a commit with those changes, and open a PR
(https://github.com/facebook/react/pull/10619)
- Cherry-pick that commit onto 15-stable, and open a PR
(https://github.com/facebook/react/pull/10621)
- Update the error codes on the `gh-pages branch` by doing the
following based on docs
(https://github.com/facebook/react/tree/master/docs#updating-facebookgithubioreact):
- Set up a sister directory to `react` with `gh-pages` checked out,
and call it `react-gh-pages`
- In your `react` repo, with `15-stable` checked out and the
error-codes update cherry-picked, run:
`cd docs && bundle rake exec && bundle exec rake fetch_remotes && bundle exec rake release`
- `cd ../react-gh-pages` and check in those changes, create a
commit/PR
- Manually test running the docs
**why make this change?:**
Even though this is just an RC, and not a final major release, we still
want the docs to be as up-to-date as possible.
**test plan:**
Run the docs locally and make sure things work.
(Flarnie will insert screenshots.)
**issue:**
https://github.com/facebook/react/issues/8854