This consolidates all of the non-template .gitignore rules into the top level .gitignore, to ignore common things more broadly, with less maintenance needed for the .gitignore files. Does not touch the templates, so that they still produce needed .gitignores as part of flutter create.
* update the color and logo for the docs site
* update the color and logo for the docs site
* remove unused file
* removed unused script code
* tweak styles for inherited names
* configs for firebase hosting
* use the implicit FIREBASE_TOKEN
* don't print every command (lowers the chance of printing secret env vars, and for realz only deploy when merging into master
* add a webmaster tools verification file
* also put the verification file at the root of our bucket
* add comment for when we can simplify this script
* add a dev/dartdoc.dart script to generate docs for the packages/ packages
* remove description
* rename readme
* change to using --include-external
* move docs to dev/docs