[REQ] Distribute versions on Homebrew

Is your feature request related to a problem? Please describe.

I have encountered this bug in OpenAPI Generator 5.4.0, which isn't present in 5.3.1 due to the change in the JSONEncodable code. There seems to also be a bugfix in the master branch 6.0.X build. Installing openapi-generator 5.3.1 via Homebrew is a longwinded though necessary process for this bug fix.

Describe the solution you'd like

I would like to be able to install multiple versions of OpenAPI Generator through Homebrew, using the syntax brew install openapi-generator@5.3.1

Describe alternatives you've considered

Reinstalling an old version of openapi-generator using Homebrew is an involved process that requires:

• finding a commit before openapi-generator was updated
• reverting Homebrew's formula list to that commit
• potentially uninstalling dependencies if you have a more recent version installed than that version of Homebrew recognises
• installing openapi-generator at that version
• reverting the git changes to your local Homebrew install
• pinning openapi-generator so that the installation doesn't again get overwritten by the updated version

The issue requests versioned OpenAPI Generator installations through Homebrew, using syntax such as brew install openapi-generator@5.3.1. Start by reviewing the current Homebrew distribution and release process; done means users can install the requested generator versions without reverting Homebrew history or pinning formulas.