Add image directive to contributing.md

CONTRIBUTING.md

@@ -54,6 +54,14 @@ Contents
    20/foo_bar
 ```
 
+To add a screenshot save the screenshot in the directory with the text and then use an image directive
+
+``` 
+.. image:: foobar.png
+
+```
+Also add both the screenshot and the modified restructured text file and commit both.
+
 Then run `make clean && make html && make latexpdf` in the root of the manual directory and it should build successfully with zero warnings! (Might take several trials to get `make latexpdf` without any errors.)
 
 ## Getting multiple Versions to Work