Update README

Structure and Contributing were both a bit out of date.

README.rst

@@ -4,27 +4,36 @@ Structure
 =========
 
 - ``api`` : Contains the HTTP API specification.
-- ``drafts`` : Contains documents which will make it into the specification
-  and/or supporting documentation at some point in the future.
-- ``event-schemas`` : Contains the `JSON Schema`_ for all Matrix events
+- ``attic``: Contains historical sections of specification for reference
+  purposes.
+- ``changelogs``: Contains change logs for the various parts of the
+  specification.
+- ``drafts``: Previously, contained documents which were under discussion for
+  future incusion into the specification and/or supporting documentation. This
+  is now historical, as we use separate discussion documents (see
+  `<CONTRIBUTING.rst>`_).
+- ``event-schemas``: Contains the `JSON Schema`_ for all Matrix events
   contained in the specification, along with example JSON files.
-- ``meta`` : Contains documents outlining the processes involved when writing
+- ``meta``: Contains documents outlining the processes involved when writing
   documents, e.g. documentation style, guidelines.
-- ``scripts`` : Contains scripts to generate formatted versions of the
+- ``scripts``: Contains scripts to generate formatted versions of the
   documentation, typically HTML.
-- ``specification`` : Contains the specification split up into sections.
-- ``supporting-docs`` : Contains additional documents which explain design 
+- ``specification``: Contains the specification split up into sections.
+- ``supporting-docs``: Contains additional documents which explain design
   decisions, examples, use cases, etc.
-- ``templating`` : Contains the templates and templating system used to
+- ``templating``: Contains the templates and templating system used to
   generate the spec.
 
 Contributing
 ============
 
 Known issues with the specification are represented as JIRA issues at
-https://matrix.org/jira/browse/SPEC
+`<https://matrix.org/jira/browse/SPEC>`_.
 
-If you want to ask more about the specification, or have suggestions for
-improvements, join us on ``#matrix-dev:matrix.org`` via https://matrix.org/beta.
+If you want to ask more about the specification, join us on
+`#matrix-dev:matrix.org <http://matrix.to/#/#matrix-dev:matrix.org>`_.
+
+If you would like to contribute to the specification or supporting
+documentation, see `<CONTRIBUTING.rst>`_.
 
 .. _JSON Schema: http://json-schema.org/