[README] Document homebrew and pip installation (#3190)

README.md

@@ -17,6 +17,14 @@ If you do not have curl, you can alternatively use a recent wget:
 
 Windows users can [download a .exe file](https://yt-dl.org/latest/youtube-dl.exe) and place it in their home directory or any other location on their [PATH](http://en.wikipedia.org/wiki/PATH_%28variable%29).
 
+OS X users can install **youtube-dl** with [Homebrew](http://brew.sh/).
+
+    brew install youtube-dl
+
+You can also use pip:
+
+    sudo pip install youtube-dl
+
 Alternatively, refer to the developer instructions below for how to check out and work with the git repository. For further options, including PGP signatures, see https://rg3.github.io/youtube-dl/download.html .
 
 # DESCRIPTION