add pypi readme

.gitignore

@@ -4,6 +4,5 @@ __pycache__/
 *-info/
 count.py
 insert.py
-README-PYPI.rst
 build/
 dist/

README-PYPI.rst

@@ -0,0 +1,46 @@
+.. image:: https://img.shields.io/travis/Damnever/pigar.svg?style=flat-square
+    :target: https://travis-ci.org/Damnever/pigar
+
+.. image:: https://img.shields.io/pypi/v/pigar.svg?style=flat-square
+    :target: https://pypi.python.org/pypi/pigar
+
+
+Features
+--------
+
+- Generate requirements for project, ``pigar`` can consider all kinds of complicated situations. In this project, `py2_requirements.txt <https://github.com/Damnever/pigar/blob/master/py2_requirements.txt>`_ and `py3_requirements.txt <https://github.com/Damnever/pigar/blob/master/py3_requirements.txt>`_ for different python versions ::
+
+    # Generate requirements.txt for current directory.
+    $ pigar
+
+    # Generate requirements for given directory in given file.
+    $ pigar -p ../dev-requirements.txt -P ../
+
+  ``pigar`` will list all files which referenced the package, for example: ::
+
+    # project/foo.py: 2,3
+    # project/bar/baz.py: 2,7,8,9
+    foobar == 3.3.3
+
+  If requirements file is overwritten over, ``pigar`` will show difference between old and new.
+
+- If you do not know the import name that belongs to a specific package (more generally, does ``Import Error: xxx`` drive you crazy?), such as ``bs4`` which may come from ``beautifulsoup4`` or ``MySQLdb`` which could come from ``MySQL_Python``, try searching for it: ::
+
+    $ pigar -s bs4 MySQLdb
+
+- To check requirements for the latest version, just do: ::
+
+    # Specific a requirements file.
+    $ pigar -c ./requirements.txt
+
+    # Or, you can leave pigar search *requirements.txt in current directory
+    # level by itself, if not found, pigar will generate requirements.txt
+    # for current project then check latest version.
+    $ pigar -c
+
+More
+----
+
+You can find more information on `GitHub <https://github.com/Damnever/pigar>`_ .
+
+