Add an example about using pip

README.md

@@ -108,6 +108,10 @@ Recipe builds can be removed via the clean command e.g.:
 
     $ ./toolchain.py clean openssl
     
+You can install package that don't require compilation with pip::
+
+    $ ./toolchain.py pip install plyer
+
 The Kivy recipe depends on several others, like the sdl* and python recipes.
 These may in turn depend on others e.g. sdl2_ttf depends on freetype, etc.
 You can think of it as follows: the kivy recipe will compile everything