docs: remove section on single: true from webpack integration (#162)
docs: remove section on single: true from webpack integration (#162)

If the user has other loaders that modify the css in his pipeline this will break, e.g. - `url()` with `url-loader` etc. and this will be a productiononly bug due to the file being processed by `css-loader` only in development.
callstack/linaria,callstack/linaria,callstack/linaria