doc: make the RST files consistently formated and other improvements.

The biggest things here are:
 * move doc/sources/*/README.rst to doc/rtd/topics/datasources
   This gives each datasource a page in the rtd docs, which make
   it easier to read.
 * consistently use the same header style throughout.
   As suggested at
   http://thomas-cokelaer.info/tutorials/sphinx/rest_syntax.html
   use:
     # with overline, for parts
     * with overline, for chapters
     =, for sections
     -, for subsections
     ^, for subsubsections
     “, for paragraphs

Also, move and re-format vendor-data documentation to rtd.

1 files changed, 16 insertions, 0 deletions

diff --git a/doc/rtd/topics/datasources/fallback.rst b/doc/rtd/topics/datasources/fallback.rst
new file mode 100644
index 00000000..1eb01dd0
--- /dev/null
+++ b/doc/rtd/topics/datasources/fallback.rst
@@ -0,0 +1,16 @@
+Fallback/None
+=============
+
+This is the fallback datasource when no other datasource can be selected. It
+is the equivalent of a empty datasource in that it provides a empty string as
+userdata and a empty dictionary as metadata. It is useful for testing as well
+as for when you do not have a need to have an actual datasource to meet your
+instance requirements (ie you just want to run modules that are not concerned
+with any external data). It is typically put at the end of the datasource
+search list so that if all other datasources are not matched, then this one
+will be so that the user is not left with an inaccessible instance.
+
+**Note:** the instance id that this datasource provides is
+``iid-datasource-none``.
+
+.. vi: textwidth=78