Fixed rst syntax, missing quote

inclement · inclement · commit f192df114a7f · 2019-01-31T16:23:20.000Z
diff --git a/doc/source/quickstart.rst b/doc/source/quickstart.rst
@@ -286,7 +286,7 @@ Overriding recipes sources
 ~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 You can override the source of any recipe using the
-``$P4A_recipename_DIR` environment variable. For instance, to test
+``$P4A_recipename_DIR`` environment variable. For instance, to test
 your own Kivy branch you might set::
 
     export P4A_kivy_DIR=/home/username/kivy
