Add short release notes for 1.0.

Fix #475.

Author: aaugustin

docs/changes.rst

@@ -0,0 +1,16 @@
+Change log
+==========
+
+1.0
+---
+
+This is the first stable version of the Debug Toolbar!
+
+It includes many new features and performance improvements as well a few
+backwards-incompatible changes to make the toolbar easier to use, extend and
+maintain in the future.
+
+You're strongly encouraged to review the installation and configuration docs
+and redo the setup in your projects.
+
+Third-party panels will need to be updated to work with this version.

docs/index.rst

@@ -9,4 +9,5 @@ Django Debug Toolbar
    tips
    panels
    commands
+   changes
    contributing

docs/installation.rst

@@ -39,6 +39,9 @@ For a simple Django project, that's all you need!
 The Debug Toolbar will automatically adjust a few settings when you start the
 development server. This happens only when the ``DEBUG`` setting is ``True``.
 
+If you're upgrading from a previous version, you should review the
+:doc:`change log <changes>` and look for specific upgrade instructions.
+
 If the automatic setup doesn't work for your project, if you want to learn
 what it does, or if you prefer defining your settings explicitly, read below.