Fix broken link in README.md

Link pointed to the right doc but the wrong extension.

Obvious fix.

Signed-off-by: Sean Walberg <sean@ertw.com>

examples/profile/README.md

@@ -1,6 +1,6 @@
 # Example InSpec Profile
 
-This example shows the implementation of an InSpec [profile](../../docs/profiles.rst).
+This example shows the implementation of an InSpec [profile](../../docs/profiles.md).
 
 ## Verify a profile