document how it works

and use .rst extension for README

README.rst

+erp5flakes is a Wrapper around pyflakes to check ERP5 code for errors.
+
+It can parse python code in products or python scripts in business
+templates, in skin folders or workflow.
+
+Install
+-------
+
+Install with pip:
+
+.. code:: shell
+
+
+    pip install -r requirements.txt
+
+Run
+---
+
+To run, ``SOFTWARE_HOME`` environment variable must be set parts/erp5/
+of the slapos software, then invoke erp5flakes with the paths of
+business templates or products to check.
+
+For example, to check all business templates from ERP5 repository inside
+a webrunner with ERP5 SR installed:
+
+.. code:: shell
+
+
+    SOFTWARE_HOME=$(dirname ~/srv/runner/software/*/parts/erp5/product) erp5flakes ~/srv/runner/software/*/parts/erp5/bt5/* ~/srv/runner/software/*/parts/erp5/product/ERP5/bootstrap/*
+
+Another example, to check ERP5Type and CMFActivity products code:
+
+.. code:: shell
+
+
+    SOFTWARE_HOME=$(dirname ~/srv/runner/software/*/parts/erp5/product) erp5flakes ~/srv/runner/software/*/parts/erp5/product/ERP5Type ~/srv/runner/software/*/parts/erp5/product/CMFActivity
+
+

README.txt

-erp5flakes is a Wrapper around pyflakes to check ERP5 code for errors.
-
-It can parse python code in products or python scripts in business templates,
-in skin folders or workflow.
-
-To use it, simply invoke erp5flakes with the path to products or business
-templates you want to check.
-

setup.py

@@ -10,7 +10,7 @@ setup(
     author_email = "jerome@nexedi.com",
     description =
       "A wrapper around pyflakes for ERP5 Products and Business Templates",
-    long_description = file('README.txt').read(),
+    long_description = file('README.rst').read(),
     license = "GPL 2",
     keywords = "erp5 zope2 pyflakes",
     url = 'https://svn.erp5.org/repos/public/erp5/trunk/utils/%s' % name,