Rewrite documentation for v0.2

[dfellis]

The new iteration of Alan has significant differences versus v0.1, including:

• Syntax changes
• Different foundational types
• Direct compilation to a binary executable
• Baked-in binding for the host language
• Different built-in subcommands
• A different focus problem (transparent GPGPU instead of automatic cloud scaling)

Much of the language has changed, so the entire documentation website needs to be rewritten.

The blog post style content probably ought to live here, as well, for easier discovery (and the Medium fad seems to have finally died down).

For those, since there are basically zero users of v0.1, I don't think a transition guide is necessary. Some ideas for blog posts include:

• What makes GPGPU so hard (dig into weird alternate history GPUs have followed vs CPUs, cover a lot of the implementation details exposed to you as a developer, and the parallels in CPUs that are instead covered up for you by the compiler and even the CPU architecture, finally how Alan helps abstract this away from you in a better way than any of the competition)
• Why should GPGPU be easy (what we have gained and lost and gained and lost with the rise and fall (or mutation) of amateur-oriented languages, why that can still be performant, and how Alan tries to be both for the amateurs and experienced developers)
• Why do developers want to patch globals in dynamic languages, why did this mostly fail, and why is this desire reasonable, then how Alan allows a facsimile of this without the downsides
• What's good and bad about explicit types, dynamic types, and inferred types. How does that balance select for developers and projects, and what does Alan choose.
• How to get set up developing with Alan