README: add MacPorts install info

[herbygillot]

tfvar has been added to MacPorts: https://ports.macports.org/port/tfvar/

[shihanng]

Thank you so much for this! I am not familiar with MacPorts. If we release a new version of tfvar, what steps do we need to take to ensure that MacPorts users will get the latest version?

For example, in Homebrew, we have a GitHub Action that pushes latest release to https://github.com/shihanng/homebrew-tfvar.

[herbygillot]

Thank you so much for this! I am not familiar with MacPorts. If we release a new version of tfvar, what steps do we need to take to ensure that MacPorts users will get the latest version?

For example, in Homebrew, we have a GitHub Action that pushes latest release to https://github.com/shihanng/homebrew-tfvar.

Every project in MacPorts is called a "port", and every port has one or more maintainers.

These are volunteers who keep a port up to date. So I'm the maintainer for tfvar's port in MacPorts, and I would keep it up to date as new versions are released. A pull request can also be opened by anyone to update the port for tfvar.

This involves updating the port's Portfile. Here's the one for tfvar: https://github.com/macports/macports-ports/blob/master/sysutils/tfvar/Portfile

[shihanng]

Thank you for the clarification and the effort 🙏 .