Add game web build artifacts

[bploeckelman]

These need to be able to be launched directly from a page view like the current version of the site. Need to determine how to include them since they can be somewhat large and there are so many of them.

Options include:

• git submodule to 'builds' repo clunky, with hard to remember commands

• git subtree to 'builds' repo easier to use, has quirks with contributing back upstream so would require keeping the repos separate, also seemed to have some issues launching certain games with this approach somehow?

• [x] direct copy into 'site' repo most straightforward option and should work well enough for the stressful deployment hour by just copying the web build folder into source tree on server and committing / pushing from there once everything was in place and finalized.

[bploeckelman]

Also need to decide whether to keep the ld##- prefix so everything lines up chronologically and it's easy to see which game was done in which jam, or to allow 'nice' naming slugs like /games/builds/game-genie but then lose the ordering.

Related to this is how to set up paths to the game related posts; /games/posts/game-genie vs /games/game-genie/post vs /posts/games/game-genie, etc...

The first option is probably easiest and allows the post markdown files to live in a sibling directory to the game builds directory rather than mingling them in elsewhere.