add better usage instructions

Change-Id: I2d435dcb187293e0b5c072ccadcf8aa4229b4505

doc/source/installation.rst

@@ -6,7 +6,10 @@ At the command line::
 
     $ pip install reno
 
-Or, if you have virtualenvwrapper installed::
+Sphinx Extension
+================
 
-    $ mkvirtualenv reno
-    $ pip install reno
+To use the Sphinx extension built into reno, install the ``[sphinx]``
+extra dependencies::
+
+    $ pip install 'reno[sphinx]'

doc/source/usage.rst

@@ -1,7 +1,120 @@
 ========
-Usage
+ Usage
 ========
 
-To use reno in a project::
+Creating New Release Notes
+==========================
 
-    import reno
+The ``reno`` command line tool is used to create a new release note
+file in the correct format and with a unique name.  The ``create``
+subcommand combines a random prefix with a "slug" value to make the
+new file with a unique name that is easy to identify again later.
+
+::
+
+    $ reno new slug-goes-here
+    Created new notes file in releasenotes/notes/95915aaedd3c48d8-slug-goes-here.yaml
+
+Within OpenStack projects, ``reno`` is often run via tox instead of
+being installed globally. For example
+
+::
+
+    $ tox -e venv -- reno new slug-goes-here
+    venv develop-inst-nodeps: /mnt/projects/release-notes-generation/reno
+    venv runtests: commands[0] | reno new slug-goes-here
+    Created new notes file in releasenotes/notes/95915aaedd3c48d8-slug-goes-here.yaml
+      venv: commands succeeded
+      congratulations :)
+    $ git status
+    Untracked files:
+      (use "git add <file>..." to include in what will be committed)
+
+        releasenotes/notes/13041418ce6be244-slug-goes-here.yaml
+
+By default the new note is created under ``./releasenotes/notes``. Use
+the ``--rel-notes-dir`` to change the parent directory (the ``notes``
+subdirectory is always appended).
+
+Editing a Release Note
+======================
+
+The note file is a YAML file with several sections. All of the text is
+interpreted as having reStructuredText formatting.
+
+prelude
+
+  General comments about the release. The prelude from all notes in a
+  section are combined, in note order, to produce a single prelude
+  introducing that release.
+
+features
+
+  A list of new major features in the release.
+
+issues
+
+  A list of known issues in the release. For example, if a new driver
+  is experimental or known to not work in some cases, it should be
+  mentioned here.
+
+upgrade
+
+  A list of upgrade notes in the release. For example, if a database
+  schema alteration is needed.
+
+critical
+
+  A list of *fixed* critical bugs.
+
+security
+
+  A list of *fixed* security issues.
+
+fixes
+
+  A list of other *fixed* bugs.
+
+other
+
+  Other notes that are important but do not fall into any of the given
+  categories.
+
+Any sections that would be blank should be left out of the note file
+entirely.
+
+::
+
+   ---
+   prelude: >
+       Replace this text with content to appear at the
+       top of the section for this release.
+   features:
+     - List new features here, or remove this section.
+   issues:
+     - List known issues here, or remove this section.
+   upgrade:
+     - List upgrade notes here, or remove this section.
+   critical:
+     - Add critical notes here, or remove this section.
+   security:
+     - Add security notes here, or remove this section.
+   fixes:
+     - Add normal bug fixes here, or remove this section.
+   other:
+     - Add other notes here, or remove this section.
+
+
+Generating a Report
+===================
+
+Run ``reno report <path-to-git-repository>`` to generate a report
+containing the release notes. The ``--branch`` argument can be used to
+generate a report for a specific branch (the default is the branch
+that is checked out). To limit the report to a subset of the available
+versions on the branch, use the ``--version`` option (it can be
+repeated).
+
+Notes are output in the order they are found by ``git log`` looking
+over the history of the branch. This is deterministic, but not
+necessarily predictable or mutable.