Keywords with special characters in them

[OllyButters]

Keywords make new web pages, which is problematic when some special characters are present, see:

https://github.com/OllyButters/puma/blob/4a38e59b4be91828f1604d35c04496b729c8847e/source/web_pages/build_htmlv2.py#L614

where I am manually ignoring a couple of keywords with / in them. Should encode this properly.