Remove `kontrol prove` and `build` flag description from docs

[palinatolmach]

There were a few changes, e.g., in --init-node-from (split into two commands), --optimize-performance, --remove-old-proofs, --cse, etc.

[palinatolmach]

Upd: after a discussion, we'e decided to remove this page, and make sure to mention the --help option earlier in the docs. We should also make sure --help output is descriptive.