Rewrite index to use scala + angular

[arvyy]

I concluded dynamic typing isn't worth the effort when it comes to prolonged maintenance of a web application. Initially I chose scheme just in case someone else would want to contribute to the project, but that hadn't happened. My chosen previous stack of kawa + my own library wrappers feels unreliable. Kawa maintainer isn't interested in communicating with potential volunteers regarding improving the language. My own wrappers are one person effort. Although scala and angular might be foreign to typical scheme programmer, they are very reliable and future-proof choices.

And ultimately, I feel the programming part of this project isn't that important, ultimately I decided it didn't matter much what the index site is written in. Most of the value lies in definition data files in types/*.scm. Writing a service / ui layer against it is relatively easy.

Additionally:

• remove "parameterized_by" (felt useless in practice)
• remove supertypes construct (felt gimmicky and ultimately unclear)
• remove "spec-values" (use description instead)
• remove "syntax-param-signature" (use value subsignature)
• change filtersets to return a list of code + name, not just code

[lassik]

I sympathize with your decision. We're all pressed for time and Scheme isn't yet a convenient tool for many jobs. If others complain that you're using the wrong tools, they should put in the work themselves - something that people very rarely do.