Most documentation isn't viewable via dub run --build=ddox

[grogancolin]

Most source files don't have a ddoc comment (/// or /+ or /**) at the top of the file, this causes the info not to show up in ddox.

A simple fix would be to add /// at the start of each file :)

[Jebbs]

I opened a pull request that allows documentation to be built with ddox, tested with dub build -b ddox.

Note that the documentation was designed to be built with the build tool included with DSFML, and I don't really know how to leverage dub to use it or to pass the ddoc macros the build tool uses when generating documentation. The documentation built with ddox won't be fully complete because of this, since the macros do a few things to help make nice documentation.

[Jebbs]

I opened up #294 to hopefully complete documentation when using ddox, but that is something that I'll have to get to later.