feat: submit formula to Homebrew core

[jsleemaster]

Submit cltree formula to Homebrew core so users can install with just brew install cltree (no custom tap needed).

Currently requires:

brew tap jsleemaster/tap
brew install cltree

Requirements

• Meet Homebrew core's "notable software" criteria
• Formula must pass brew audit --strict

References

• https://docs.brew.sh/Acceptable-Formulae
• https://docs.brew.sh/How-To-Open-a-Homebrew-Pull-Request