doc: separate python README

python/README.md

@@ -0,0 +1,31 @@
+# Control NanoVNA from python script
+
+NanoVNA is able to be controlled via USB serial interface from PC. There are sample scripts in this directory.
+
+## Preparation
+
+    $ cd python
+    $ pip install numpy
+    $ pip install scikit-rf   
+
+## Run
+
+### Plot reflection LOGMAG.
+
+    $ ./nanovna.py -p
+
+### Plot transmission LOGMAG.
+
+    $ ./nanovna.py -p -P 1
+
+### Plot smithchart.
+
+    $ ./nanovna.py -s
+
+### Show usage.
+
+    $ ./nanovna.py -h
+
+## Using in Jupyter Notebook
+
+To use NanoVNA from Jupyter notebook, see [this page](/python/NanoVNA-example.ipynb).