Fix build err

Hi,

I would like to help out with some updates to your documentation. As a starting point, I have familiarised myself with the readthedocs.org site and how you publish your doco. My commits fix a couple of the errors I noticed while looking at both the HTML and PDF generated by that site.

 Notes on the Remove Indexing Statements commit: 
* readthedocs.org was not generating an index at all for the PDF document. For the HTML pages, it had a link on the TOC to an 'index' but that index only showed one entry for 'Getting Started' (due to the .. index markup in the file).
* the output from the PDF build on readthedocs has two messages. Near the start of build: "Writing index file GitExtensionsDoc.idx" and at the end: "No file GitExtensionsDoc.ind"
I was wondering if these two files are the same and there is a bug in the readthedocs.org site code where it creates an index file but uses the wrong name at the end of the process? From my reading (the Sphinx doco?) an index should automatically be created.
* if an index is required for the doco, then could probably get it working for the HTML pages by adding .. index to each chapter, but still would not work for the PDF.

I have not tested these changes via the manual generation as per your README file - I had trouble installing the software and gave up! I figure if you are using the readthedocs.org site as your 'official' public documentation, then as long as it works there I don't need to manually generate it.

I have also tried to fix the 'blank' pages issue by manipulating page content but nothing I tried worked!