- add `make js`, deprecating `make javascripts`
- add `make css`, deprecating `make generate-stylesheets` and
`make stylesheets-check`
- changed the unclean css check to only run on CI
- add JS linting via eslint with basic configuration and fixed
discovered issues
- changed autoprefixer to use official `postcss-cli` avoiding the need
to loop in the makefile
- moved browserslist to package.json so other future tools can use it
too.
- update documentation for new make targets and added JS section
This makes it easier for user who want to theme but
don't have the ability to know how to customize templates
all that is required is a change in a config option
The reason why I chose the DEFAULT_THEME as variable,
as perhaps in the future we will allow users to chose their
theme whon logged in just like we do with languages
