Casks have a `DeprecateDisable` `unreachable` reason that we use when
a website is unreachable (e.g., anti-bot protections make the asset
inaccessible). Formulae have similar reasons like `repo_archived`
but none of the existing reasons account for the situation where a
project is supported and maintained but it's not possible to reach the
server outside of a browser to download release assets. This adds the
`unreachable` reason to the `FORMULA_DEPRECATE_DISABLE_REASONS` hash,
so we can use it in formulae as well.
Combine the separate formulae, cask and code deprecation
docs into a single page with shared lifecycle overview,
per-type criteria and `redirect_from` for old URLs.
- add `docs/Deprecating-Disabling-and-Removing.md`
- add code deprecation policy (`odeprecated`/`odisabled`
lifecycle, API classification, CLI flags, env vars)
- delete old `-Formulae` and `-Casks` pages, redirect
via `redirect_from` on the new page
- update cross-references in cookbooks, maintainer guide,
`Releases.md`, `index.md` and `formula.rb`
- add missing `index.md` entries for `Homebrew-and-Java`,
`Linux-CI`
Sam Ford