brew cask: add page (#1376)

pages/osx/brew-cask.md

@@ -0,0 +1,31 @@
+# brew cask
+
+> Package manager for macOS applications distributed as binaries.
+
+- Search for casks:
+
+`brew cask search {{text}}`
+
+- Install a cask:
+
+`brew cask install {{cask_name}}`
+
+- List all installed casks:
+
+`brew cask list`
+
+- List installed casks that have newer versions available:
+
+`brew cask outdated`
+
+- Upgrade an installed cask to its latest version:
+
+`brew cask reinstall {{cask_name}}`
+
+- Uninstall a cask:
+
+`brew cask uninstall {{cask_name}}`
+
+- Display information about a given cask:
+
+`brew cask info {{cask_name}}`