Brew cask has been deprecated (#1732)

Author: chriscn

README.md

@@ -19,7 +19,7 @@ Use IPFS Desktop to get acquainted with IPFS without needing to touch the termin
 
 ### Quick-install shortcuts
 
-- **Mac:** [IPFS-Desktop-0.13.2.dmg](https://github.com/ipfs-shipyard/ipfs-desktop/releases/download/v0.13.2/IPFS-Desktop-0.13.2.dmg) or `brew cask install ipfs`
+- **Mac:** [IPFS-Desktop-0.13.2.dmg](https://github.com/ipfs-shipyard/ipfs-desktop/releases/download/v0.13.2/IPFS-Desktop-0.13.2.dmg) or `brew install --cask ipfs`
 - **Windows:** [IPFS-Desktop-Setup-0.13.2.exe](https://github.com/ipfs-shipyard/ipfs-desktop/releases/download/v0.13.2/IPFS-Desktop-Setup-0.13.2.exe) or `choco install ipfs-desktop`
 - **Linux:** See [installation options](#install) below