Default documentation to most recent version

[davidwilby]

Currently, the documentation served at https://gatenlp.github.io/gate-teamware/ defaults to the development documentation, but should perhaps display the most recent version instead by default.

On a related note, I notice that the versions displayed in the drop down are in numerical order, e.g.

0.3.0
0.4.0

but ideally the most recent version should be at the top.