GH has different HardBreaks behaviour for markdown comments and documents.

Comments have hard breaks and documents have soft breaks - therefore Gitea's rendering will always be different from GH's if we only provide one setting.

Here we split the setting in to two - one for documents and one for comments and other things.

Signed-off-by: Andrew Thornton art27@cantab.net

Changes to index.js as per @silverwind 
Co-authored-by: silverwind <me@silverwind.io>

Changes to docs as per @guillep2k 
Co-authored-by: guillep2k <18600385+guillep2k@users.noreply.github.com>