Update README file with current check info

Post our current error list up front since we have
a proper README now.

Change-Id: I33576c2c4362d69e93c238cdc31322d5f327029b

README.rst

@@ -4,12 +4,36 @@ bash8
 
 A pep8 equivalent for bash scripts
 
-* Free software: Apache license
-* Documentation: http://docs.openstack.org/developer/bash8
-* Source: http://git.openstack.org/cgit/openstack-dev/bash8
-* Bugs: http://bugs.launchpad.net/bash8
+This program attempts to be an automated style checker for bash scripts
+to fill the same part of code review that pep8 does in most OpenStack
+projects. It started from humble beginnings in the DevStack project,
+and will continue to evolve over time.
 
-Features
---------
+- Free software: Apache license
+- Documentation: http://docs.openstack.org/developer/bash8
+- Source: http://git.openstack.org/cgit/openstack-dev/bash8
+- Bugs: http://bugs.launchpad.net/bash8
 
-* TODO
+Currently Supported Checks
+--------------------------
+
+Errors
+~~~~~~
+
+Basic white space errors, for consistent indenting
+
+- E001: check that lines do not end with trailing whitespace
+- E002: ensure that indents are only spaces, and not hard tabs
+- E003: ensure all indents are a multiple of 4 spaces
+- E004: file did not end with a newline
+
+Structure Errors
+~~~~~~~~~~~~~~~~
+
+A set of rules that help keep things consistent in control blocks.
+These are ignored on long lines that have a continuation, because
+unrolling that is kind of "interesting"
+
+- E010: *do* not on the same line as *for*
+- E011: *then* not on the same line as *if*
+- E012: heredoc didn't end before EOF