Update the documentation

The README file is lying yet.

README.rst

@@ -0,0 +1,65 @@
+Flask-Logging-Extras
+====================
+
+[travis button] [coveralls button] [pypi button] [documentation button]
+
+Flask-Logging-Extras adds additional logging features for Flask applications.
+
+The only feature implemented now is adding extra arguments to the format
+string, like this:
+
+.. code-block:: python
+
+   fmt = '[%(asctime)s] [%(levelname)s] [%(category)s] %(message'
+   # Initialize log handlers as usual, like creating a FileHandler, and
+   # assign fmt to it as a format string
+
+   current_app.logger.info('this is the message, as usual',
+                           category='fancy-category')
+
+### Installation
+
+pip will be available (hopefully) soon.
+
+If you prefer to install from source, you can clone this repo and run
+
+.. code-block:: sh
+
+   $ python setup.py install
+
+Usage
+-----
+
+[View the documentation online] (http://flask-jwt-extended.readthedocs.io/en/latest/)
+
+
+Testing and Code Coverage
+-------------------------
+
+We require 100% code coverage in our unit tests. We run all the unit tests
+with tox, which will test against python2.7, 3.3, 3.4, and 3.5.
+
+Running tox will print out a code coverage report.  Coverage report is also
+available on codecov.
+
+tox is running automatically for every push in Travis-CI.  To run tox on
+your local machine, you can simply invoke it with the `tox` command.
+
+Generating Documentation
+------------------------
+
+You can generate a local copy of the documentation.  First, make sure you have
+the flask sphinx theme available.  You can get it with
+
+.. code-block:: sh
+   $ pip install Flask-Sphinx-Themes
+
+Then in the `docs/` directory, run
+
+.. code-block:: sh
+   $ make clean && make html
+
+License
+-------
+
+This module is available under the BSD license.

flask_logging_extras/__init__.py

@@ -53,7 +53,11 @@ def register_logger_class(cls=FlaskExtraLogger):
     """
     Register a new logger class
 
-    It is effectively a wrapper around logging.setLoggerClass().
+    It is effectively a wrapper around logging.setLoggerClass(), with an
+    added check to make sure the class can be used as a logger.
+
+    To use the extra features of the logger class in a Flask app, you must
+    call it before the app is instantiated.
     """
 
     if not issubclass(cls, logging.Logger):