Replace \href with \url if possible

[h4b4n3r0]

The current Link2Latex implementation replaces html hrefs of the form <a href=URL>DESCRIPTION</a> always with \href{DESCRIPTION}{URL}. However, if description and url are identical e.g. because of the original markdown <URL> or [URL](URL), latex's \href{URL}{URL} can be simlified with \url{URL}.