Reduce dom size

[syeopite]

The HTML produced by npf-renderer contains a lot of useless classes and tags. For example the inline-formatted-content span that surrounds the entire contents of text blocks when something is inline formatted.

This should be fixed. The output of npf-renderer should be as small as possible

[syeopite]

With #5 increasing the size of the HTML output even more, this needs to be higher priority