Update publish instructions

Author: maclockard

PUBLISH.md

@@ -4,6 +4,8 @@
 - Checkout new branch with name like `hex-fork.3` (check existing branches for what number to use)
 - `npm install`
 - `npm run pub`
+- `cd build/quicktype-core && npm run build && cd ..`
 - `./script/make-publish-branch.sh`
+- Remove `dist` from `.gitignore`
 - Commit and push branch
 - Update the main `hex` repo to use the new branch