* Add stability to config options
* Reject unstable options
* Add note to docs
* Use enum validator in e-h-embassy
* Generate a list for enumerated values
* Don't allow line-wrapping headers
* Center default/allowed values
* Changelog
* Display stability under name
* Remove - from Allowed value when option has no constraints
* Mark more options as unstable
* Include a hint in the unstable error
* Extract value and validator modules
* Clean up
* Replace tuples with ConfigOption
* Move generate.rs
* Further refactor write_doc_table_line
* Carry around the config option, too
* Move markdown table processing out of random places
* Compare prettified json, use pretty_assertions to diff it
* Work with Vec
* Emit enumerated cfgs in one place
