V2 -- Add static directory to build step

[sthzg]

Originates from: react-webpack-generators/generator-react-webpack#270

• add directory src/static
• provide README in src/static
• update copy run script to recursively copy the directory to dist/static
• refactor favicon to be copied via the static dir
• reference favicon from new location in index.html

Note: in further iterations the build step could be improved by #49, which will allow us to build dynamic/configurable paths to the static/asset/... directories (e.g. when users build apps to be hosted on sub-directories, where src="/static/foo.jpg" would fail).

[sthzg]

Closed with #55