Explain in M-STATIC-VERIFICATION general motivation for custom lints we picked & expand

Add a few more words that they make code look nicer, etc.

Also add `redundant_pub_crate = "allow"`.

TODO: Any statistics which lints are usually enable / suppressed in ecosystem? IIRC there was an experiment about that a few years ago, but can't find it anymore.

Start at the M-STATIC-VERIFICATION section and inspect the Rust lint configuration to find where custom lints are documented and where redundant_pub_crate can be allowed. Done means the motivation is expanded, the requested lint setting is added, and the statistics TODO is resolved or clearly scoped.

Written by the indexing model from the issue text.