Add a custom Liquid filter for semantic-version sorting

[briandominick]

Arrays that contain strings of semantic software versions (1.2.12, 1.2.1-rc1,1.2.0alpha2,1.2.0alpha12, etc) should be sortable by that version in some sensible way.

https://medium.com/@edgar/how-to-compare-semantic-version-strings-in-ruby-95fbf067de32