README: Include basic project information + markup

Author: einarf

README.md

@@ -1,22 +1,86 @@
+# pyopengltk
+
 Tkinter - OpenGL Frame using ctypes
 
+* [pyopengltk on Github](https://github.com/jonwright/pyopengltk)
+* [pyopengltk on PyPI](https://pypi.org/project/pyopengltk/)
+
 An opengl frame for pyopengl-tkinter based on ctypes (no togl compilation)
 
 Collected together by Jon Wright, Jan 2018.
 
-Based on the work of others
+## Basic Example
+
+This example creates a window containing an `OpenGLFrame`
+filling the entire window. We configure it to animate
+(constantly redraw) clearing the screen using a green color.
+A simple framerate counter is included.
+The context information is printed to the terminal.
+
+```python
+import time
+import tkinter
+from OpenGL import GL
+from pyopengltk import OpenGLFrame
+
+class AppOgl(OpenGLFrame):
+
+    def initgl(self):
+        """Initalize gl states when the frame is created"""
+        GL.glViewport(0, 0, self.width, self.height)
+        GL.glClearColor(0.0, 1.0, 0.0, 0.0)    
+        self.start = time.time()
+        self.nframes = 0
+
+    def redraw(self):
+        """Render a single frame"""
+        GL.glClear(GL.GL_COLOR_BUFFER_BIT)
+        tm = time.time() - self.start
+        self.nframes += 1
+        print("fps",self.nframes / tm, end="\r" )
+
+
+if __name__ == '__main__':
+    root = tkinter.Tk()
+    app = AppOgl(root, width=320, height=200)
+    app.pack(fill=tkinter.BOTH, expand=tkinter.YES)
+    app.animate = 1
+    app.after(100, app.printContext)
+    app.mainloop()
+```
+
+The repository on Github also contains more examples.
+
+## Install
+
+From PyPI:
+
+```
+pip install pyopengltk
+```
+
+From source:
+
+```
+git clone https://github.com/jonwright/pyopengltk
+cd pyopengltk
+pip install .
+```
+
+## Attributions
+
+Based on the work of others.
+
+### C + Tcl/Tk example:
+
+* Project URL : http://github.com/codeplea/opengl-tcltk/ (zlib license)
+* Article at : https://codeplea.com/opengl-with-c-and-tcl-tk
 
-C + Tcl/Tk example:
- http://github.com/codeplea/opengl-tcltk/
- (zlib license)
- Article at:
-   https://codeplea.com/opengl-with-c-and-tcl-tk
+### Python + Tkinter (no pyopengl) example:
 
-Python + Tkinter (no pyopengl) example:
- http://github.com/arcanosam/pytkogl/
- (The Code Project Open License)
- Article at 
-  http://www.codeproject.com/Articles/1073475/OpenGL-in-Python-with-TKinter
+* Project URL : http://github.com/arcanosam/pytkogl/ (The Code Project Open License)
+* Article at: http://www.codeproject.com/Articles/1073475/OpenGL-in-Python-with-TKinter
 
-Large regions of code copied from pyopengl/Tk/__init__.py
+### pyopengl
 
+* Large regions of code copied from `pyopengl/Tk/__init__.py`.