Update the website

[Lassi Kortela]

Could you update the Sagittarius homepage so it has at least:

• A short explanation of Sagittarius
• Installation instructions
• HTML copy of manual (already present)
• Link to source control (BitBucket / GitHub) and bug tracker
• Email address for contact

We currently redirect https://sagittarius.scheme.org/ to https://ktakashi.github.io/ but the current page doesn’t really explain what Sagittarius is and how to find it.

[Takashi Kato]

The page was initially meant to be just hosting the documentation (and in a parallel world, I’d make a proper domain), but I think you’re right. I’ll add some explanation and so.

[Takashi Kato]

Put more information on https://ktakashi.github.io