Rename README to README.md

Author: jaketheduque

pybind/README pybind/README.mdpybind/README renamed to pybind/README.md

@@ -20,4 +20,4 @@
 - Switch to the terminal window in the `pybind` directory
 - Run `python run.py ../tests/simulated-unobstructed-airway_v0.0.0/ip900ap`
   - `matplotlib` may need to be installed for the script to run successfully
-- A plot of the raw PPG data overlayed with the calculated SpO2 should appear
+- A plot of the raw PPG data overlayed with the calculated SpO2 should appear