update website

[silky]

i've put together a basic (hacky) hakyll website, based on some others i've made in the past

it's got some basic content on there, but needs:

• application typeform?
• slack community link
• some misc. content
• random TODO notes (search for "TODO")

anyone feel free to try and run it locally and confirm that it looks reasonable.

i guess, following @marcosh 's comment here - FixPlanet/org#8 - we don't really need to wait until it's ready for applications to publish it; in many ways we probably shouldn't. but it'd be good to have a minimal amount of information there, and indicate we're in a kind of "beta" feedback stage, before an actual launch later on