sphinx: copy basic instructions from readme

Author: julianoes

mavsdk/source/index.rst

@@ -20,6 +20,42 @@ MAVSDK-Python API reference
    system
    plugins/index
 
+Important Notes
+---------------
+
+- Python 3.6+ is required.
+- You may need to run ``pip3`` instead of ``pip`` and ``python3`` instead of ``python``, depending of your system defaults.
+- Auterion has a _Getting started with MAVSDK-Python: https://auterion.com/getting-started-with-mavsdk-python/ guide if you're a beginner and not sure where to start.
+
+Install using pip from PyPi
+---------------------------
+
+To install simply run:
+
+  pip3 install mavsdk
+
+
+The package contains ``mavsdk_server`` already (previously called "backend"), which is started automatically when connecting (e.g. ``await drone.connect()``). Have a look at the examples to see it used in practice. It will be something like:
+
+  python
+  from mavsdk import System
+
+  ...
+
+  drone = System()
+  await drone.connect(system_address="udp://:14540")
+
+
+Note: ``System()`` takes two named parameters: ``mavsdk_server_address`` and ``port``. When left empty, they default to ``None`` and ``50051``, respectively, and ``mavsdk_server -p 50051`` is run by ``await drone.connect()``. If ``mavsdk_server_address`` is set (e.g. to "localhost"), then ``await drone.connect()`` will not start the embedded ``mavsdk_server`` and will try to connect to a server running at this address. This is useful for platforms where ``mavsdk_server`` does not come embedded, for debugging purposes, and for running ``mavsdk_server`` in a place different than where the MAVSDK-Python script is run.
+
+Run the examples
+----------------
+
+Once the package has been installed, the examples can be run:
+
+  examples/takeoff_and_land.py
+
+The examples assume that the embedded ``mavsdk_server`` binary can be run. In some cases (e.g. on Raspberry Pi), it may be necessary to run ``mavsdk_server`` manually, and therefore to set ``mavsdk_server_address='localhost'`` as described above.
 
 
 Indices and tables