Small edits while reading

Markup literals correctly.

Change this:
  with it's own field type which does not too much text analysis.
to this:
  with its own field type which does not do too much text analysis.

Make the docs match the installed code

Fix Pythonism

In XML it's ``stored="true"``, not ``stored=True``.

Markup, typo, some extra detail (solrconfig.xml, schema.xml).

Added note about doc edits