docs: add note how to install on windows (#68)

Author: bednar

README.rst

@@ -72,11 +72,17 @@ InfluxDB python library uses `RxPY <https://github.com/ReactiveX/RxPY>`__ - The
 
 **Python 3.6** or later is required.
 
+.. note::
+
+    **Windows**:
+
+    The client uses ``ciso8601`` for parsing dates. ``ciso8601`` is much faster than built-in Python datetime.
+    Since it's written as a ``C`` module you have to install `Visual C++ Build Tools 2015 <http://go.microsoft.com/fwlink/?LinkId=691126&fixForIE=.exe>`_ to build ``ciso8601`` binaries.
 
 pip install
 ^^^^^^^^^^^
 
-The python package is hosted on Github, you can install latest version directly:
+The python package is hosted on `PyPI <https://pypi.org/project/influxdb-client/>`_, you can install latest version directly:
 
 .. code-block:: sh