Documentation updates (live and pending)

Hi everybody,

I’ve pushed a bunch of clean-ups on https://docs.simplicity-lang.org/, including streamlining our Welcome pages and some other material, and removing a few obsolete or redundant pages. We also have Simplex documentation there for the first time.

The landing page and Quickstart tutorial have a pending major revision (with Quickstarts available for Rust, bash, and Python (experimental)). I have staged that revision at Simplicity is a typed, combinator-based smart contract language for Bitcoin-like blockchains, with formally specified semantics and predictable execution costs. - Simplicity (draft) (a personal github.io page) to ask for more feedback before rolling it out. That also includes a “Try It” page that lets you run some SimplicityHL code right in your browser (invented by @stringhandler), although I’m still struggling with the CSS formatting for that page, so depending on when you look at it, it may look out-of-place within the docs site.

I would love to hear any feedback on these changes or any other suggestions or requests for our developer documentation!

I’ve launched all of these pending changes on the live documentation site at https://docs.simplicity-lang.org/. Enjoy! Let me know if you have any questions, comments, or requests for additional documentation.