Feature request: log the reason for pinning formulas

[andreineculau]

Output of brew config

HOMEBREW_VERSION: 4.0.1-60-g6ad9294
ORIGIN: https://github.com/Homebrew/brew
HEAD: 6ad92949e910041416d84a53966ec46b873e069f
Last commit: 26 hours ago
Core tap origin: https://github.com/Homebrew/homebrew-core
Core tap HEAD: c4bd29b2a369e76e357c39cb7d4dec534a5dde5e
Core tap last commit: 7 days ago
Core tap branch: master
Core tap JSON: 18 Feb 16:30 UTC
HOMEBREW_PREFIX: /opt/homebrew
HOMEBREW_BROWSER: open
HOMEBREW_CASK_OPTS: []
HOMEBREW_EDITOR: /opt/homebrew/bin/emacs -nw
HOMEBREW_MAKE_JOBS: 8
HOMEBREW_NO_ANALYTICS: set
HOMEBREW_NO_AUTO_UPDATE: set
HOMEBREW_NO_INSTALL_CLEANUP: set
Homebrew Ruby: 2.6.10 => /System/Library/Frameworks/Ruby.framework/Versions/2.6/usr/bin/ruby
CPU: octa-core 64-bit arm_firestorm_icestorm
Clang: 14.0.0 build 1400
Git: 2.38.2 => /opt/homebrew/bin/git
Warning: --ssl is an insecure option, consider --ssl-reqd instead
Curl: 7.86.0 => /usr/bin/curl
macOS: 13.2.1-arm64
CLT: 14.2.0.0.1.1668646533
Xcode: 14.2
Rosetta 2: false

Output of brew doctor

Please note that these warnings are just used to help the Homebrew maintainers
with debugging if you file an issue. If everything you use Homebrew for is
working fine: please don't worry or file an issue; just ignore this. Thanks!

Warning: Some installed formulae are deprecated or disabled.
You should find replacements for the following formulae:
  rebar

Warning: Putting non-prefixed coreutils in your path can cause GMP builds to fail.

Warning: Putting non-prefixed findutils in your path can cause python builds to fail.

Warning: You have unlinked kegs in your Cellar.
Leaving kegs unlinked can lead to build-trouble and cause formulae that depend on
those kegs to fail to run properly once built. Run `brew link` on these:
  make
  python@3.11

Description of issue

When using brew pin, there is no way currently to log the reason for pinning. It is easy to pin stuff, and months later see that brew upgrade will warn about skipping the pinned formulas, but you have no clue whether it is now safe to unpin.

I currently cheat and write brew pin ... # reason for pinning so that I can find the reason in the shell history.