Prevent hyphenation of entity links generated by MrDocs

[anarthal]

Links to C++ entities are currently subject to be split across several lines through hyphenation. For example:

Live: https://anarthal.github.io/mysql-mrdocs-v1/mysql/reference/boost/mysql/sequence.html (please ignore the other glitches, they're in the process of being solved).

Breaking the name of a C++ entity looks weird, as it's not legal in C++. Entity names should be limited in number of characters, so it should be safe to apply whatever CSS property is required to make the word be entirely on the next line.