feat(developer): add api-extractor and api-documenter and config

Relates to #10207.

Adds @microsoft/api-extractor and @microsoft/api-documenter NPM
packages for validating and generating API documentation from Typescript
modules.

Adds basic configuration for each module that we will be publishing at
this time.

api-extractor's output will be emitted to /developer/docs/api/etc/, for
future release comparisons. A baseline output will be committed
separately.

The build outputs will be in /developer/build/docs and the intermediate
files will be in /developer/build/api.

Note that at this time, we will not enable the checks and validations.
That is a task for alpha rather than beta. The primary intent at this
time is to select a solid, well-supported toolchain for generating the
API documentation for kmc.