Update getting-started.md

[Fabien-Chouteau]

No description provided.

[simonjwright]

(1) Line 8 shouldn’t mention macOS.

(2) On macOS, there’s an issue with System Integrity Protection: the alr binary is quarantined,

$ xattr -v bin/alr 
bin/alr: com.apple.quarantine

If you try to run it on recent versions of macOS, you’ll get a popup saying '“alr” cannot be opened because the developer cannot be verified.' and inviting you to move it to the bin.

The way round this is to remove the quarantine attribute,

$ xattr -d com.apple.quarantine bin/alr

[mosteo]

Just a typo.

Also adding the info provided by Simon looks useful for macOS.

[Fabien-Chouteau]

Thanks both 👍