clarifying extension options

README.md

@@ -27,16 +27,17 @@ An example<sup>[1](#fn1)</sup> of the first is: ![expected_output/doubleExperime
 
 #### Changing the Layout and Developing New Capability
 
-Users who want to change the layout of the tables, or develop new tables will need to try and understand  _pyesdoc_ which does the heavy lifting via Python class instances for manipulating ESDOC documents. 
+Users who want to change the layout of the tables, or develop new tables may need to try and understand  _pyesdoc_ which does the heavy lifting via Python class instances for manipulating ESDOC documents. 
 
+* If you want to change the layout only, then you can play with the jinja2 templates alone, you won't need to understand _pyesdoc_.
 * The documentation for _pyesdoc_ itself is rather sparse right now, but you can't go too far wrong by just playing at the console and using introspection. 
 * You can also inspect the attributes and structure by looking at the [canonical schema description](https://github.com/ES-DOC/esdoc-cim-v2-schema). For example [this code](https://github.com/ES-DOC/esdoc-cim-v2-schema/blob/bdf6e8268da0e0ba7f7bc3252644042fc79c3434/designing_classes.py#L173) is the definition of an _Experiment_ and you can see the attributes which an Experiment instance must have.
 * A key concept you will need to deal with is that the documents are all linked together. As you navigate around them pythonically you will get the title and uid and types of other documents in links (e.g. the Experiment references _Requirements_), and sometimes you will need to pull the full description of those via the UID. Code to do this is included. Note how the additional requirements [are found](https://github.com/bnlawrence/esdoc4scientists/blob/ad64f25f111ff7f7a3b6d1de3d96ebe6a89eaeb0/experiment.py#L226) for the example above.
 *  If you get some new things working please contribute them back here!
 
 #### Acknowledgements
 
-This would not have been possible without some initial help from [Mark Greenslade](https://github.com/momipsl), the author of pyesdoc.
+This would not have been possible without some initial help from [Mark Greenslade](https://github.com/momipsl), the author of _pyesdoc_.
 
 <a name="fn1">[1]</a>:  Note that this is a poor quality jpg rendering of the [actual pdf](expected_output/double_cropped.pdf) in the repository. The workflow for this was to crop the [original pdf](expected_output/double.pdf) output using pdf-crop-margins, then convert to jpg using an [online converter](http://convert-my-image.com/PdfToJpg) (my usual goto for this sort of work, ImageMagick, didn't like the grayscale).