Non-urgent but mild usability improvement on homebrew recipe and tap usage.

Related: #597

With this change the homebrew formula can be installed as:

brew tap dagu-dev/dagu && brew install dagu
OR
brew install dagu-dev/dagu/dagu

Note: this takes advantage of conventions for naming in homebrew and requires setting up a repo of dagu-dev/homebrew-dagu which is then automatically referenced when doing brew tap dagu-dev/dagu.

Example when I try to do the brew tap command before anything is setup:

❯ brew tap dagu-dev/dagu
==> Tapping dagu-dev/dagu
Cloning into '/opt/homebrew/Library/Taps/dagu-dev/homebrew-dagu'...
remote: Repository not found.
fatal: repository 'https://github.com/dagu-dev/homebrew-dagu/' not found

I can't test it out, but I believe this will dual push the homebrew recipe to allow for graceful retirement of former location.

Sorry for the auto-format of yaml from single to double quotes, I can revert that part if undesired.

TODO

• Setup repo dagu-dev/homebrew-dagu and ensure this GH actions has permissions to it