Add instructions for installing swctl on macOS

[CodePrometheus]

swctl is now available in brew.

[wu-sheng]

There is only 0.14 available there. Could you add from 0.11? And the brew only monitor newer(e.g. 0.15) release and automatically package and host here?

[CodePrometheus]

There is only 0.14 available there. Could you add from 0.11? And the brew only monitor newer(e.g. 0.15) release and automatically package and host here?

By default, brew install will only download the latest version. If we want to support multiple version swctl on brew, there are two ways:

1. I add SwctlAT11, SwctlAT12... one by one in the core repository following our releases
2. Users modify the source code to manually specify the download

[wu-sheng]

Is way one listing all versions on the same page?

[CodePrometheus]

Is way one listing all versions on the same page?

AFAIK, there is no other way except adding version Classes one by one. For example, for openjdk, multiple classes are maintained in the core repo, this maintenance method is often used for large and widely used basic class libraries, such as python, mysql, go, etc.

[wu-sheng]

OK, then let skip that. Thanks for the explanation.