Convert README to markdown for better github presentation

README.txt → README.md

-PyQtGraph - A pure-Python graphics library for PyQt/PySide
+PyQtGraph
+=========
+
+A pure-Python graphics library for PyQt/PySide
 Copyright 2012 Luke Campagnola, University of North Carolina at Chapel Hill
 http://www.pyqtgraph.org
 
-Maintainer:
-    Luke Campagnola   ('luke.campagnola@%s.com' % 'gmail')
+Maintainer
+----------
+   * Luke Campagnola   ('luke.campagnola@%s.com' % 'gmail')
 
-Contributors:
-    Megan Kratz
-    Paul Manis
-    Ingo Breßler
-    Christian Gavin
-    Michael Cristopher Hogg
-    Ulrich Leutner
-    Felix Schill
-    Guillaume Poulin
+Contributors
+------------
+   * Megan Kratz
+   * Paul Manis
+   * Ingo Breßler
+   * Christian Gavin
+   * Michael Cristopher Hogg
+   * Ulrich Leutner
+   * Felix Schill
+   * Guillaume Poulin
 
-Requirements:
+Requirements
+------------
     PyQt 4.7+ or PySide
     python 2.6, 2.7, or 3.x
     numpy, scipy
     For 3D graphics: pyopengl
     Known to run on Windows, Linux, and Mac.
 
-Support:
+Support
+-------
     Post at the mailing list / forum:
     https://groups.google.com/forum/?fromgroups#!forum/pyqtgraph
 
-Installation Methods:
-    - To use with a specific project, simply copy the pyqtgraph subdirectory 
-      anywhere that is importable from your project 
-    - To install system-wide from source distribution:
-         $ python setup.py install
-    - For instalation packages, see the website (pyqtgraph.org)    
+Installation Methods
+--------------------
+    * To use with a specific project, simply copy the pyqtgraph subdirectory
+      anywhere that is importable from your project
+    * To install system-wide from source distribution:
+         `$ python setup.py install`
+    * For instalation packages, see the website (pyqtgraph.org)
 
-Documentation:
-    There are many examples; run "python -m pyqtgraph.examples" for a menu.
+Documentation
+-------------
+    There are many examples; run `python -m pyqtgraph.examples` for a menu.
     Some (incomplete) documentation exists at this time.
-    - Easiest place to get documentation is at 
+    * Easiest place to get documentation is at
       http://www.pyqtgraph.org/documentation
-    - If you acquired this code as a .tar.gz file from the website, then you can also look in 
+    * If you acquired this code as a .tar.gz file from the website, then you can also look in
       doc/html.
-    - If you acquired this code via BZR, then you can build the documentation using sphinx.
+    * If you acquired this code via GitHub, then you can build the documentation using sphinx.
       From the documentation directory, run:
-          $ make html  
-    Please feel free to pester Luke or post to the forum if you need a specific 
+          `$ make html`
+    Please feel free to pester Luke or post to the forum if you need a specific
     section of documentation.