Windows 10 instructions (esp8266#4797)

* Instructions update

added correction for Windows 10 git install directory

* Update installing.md

* Update installing.rst

* Reminder for VisualMicro

install clarifications

* tidy up links 

markup works differently in rst vs md

* formatting cleanup

* corrected default sketch directory

the default Arduino Sketchbook directory is C:\users\{username}\Documents\Arduino (thanks @Juppit)

esp8266#4797 (comment)

* check for directory before creating

doc/installing.rst

@@ -33,6 +33,10 @@ You may optionally use *staging* boards manager package link:
 This may contain some new features, but at the same time, some things
 might be broken.
 
+For more information on the Arduino Board Manager, see:
+
+- https://www.arduino.cc/en/Guide/Libraries
+
 Using git version
 -----------------
 
@@ -42,13 +46,84 @@ developers.
 Prerequisites
 ~~~~~~~~~~~~~
 
--  Arduino 1.6.8 (or newer, if you know what you are doing)
+-  Arduino 1.6.8 (or newer, current working version is 1.8.5)
 -  git
--  python 2.7
--  terminal, console, or command prompt (depending on you OS)
+-  Python_ 2.7 (http://python.org)
+-  terminal, console, or command prompt (depending on your OS)
 -  Internet connection
 
-Instructions
+Instructions - Windows 10
+~~~~~~~~~~~~
+- First, make sure you don't already have the ESP8266 library installed using the Board Manager (see above)
+
+- Install git for Windows (if not already; see https://git-scm.com/download/win)
+
+-  Open a command prompt (cmd) and go to Arduino default directory. This is typically the
+   *sketchbook* directory (usually ``C:\users\{username}\Documents\Arduino`` where the environment variable ``%USERPROFILE%`` usually contains ``C:\users\{username}``)
+
+-  Clone this repository into hardware/esp8266com/esp8266 directory.
+
+   .. code:: bash
+      
+       cd %USERPROFILE%\Documents\Arduino\
+       if not exist hardware mkdir hardware
+       cd hardware
+       if not exist esp8266com mkdir esp8266com
+       cd esp8266com
+       git clone https://github.com/esp8266/Arduino.git esp8266
+
+   You should end up with the following directory structure in
+   
+   ``C:\Users\{your username}\Documents\``
+
+   .. code:: bash
+
+       Arduino
+       |
+       --- libraries
+       --- hardware
+           |
+           --- esp8266com
+               |
+               --- esp8266
+                   |
+                   --- bootloaders
+                   --- cores
+                   --- doc
+                   --- libraries
+                   --- package
+                   --- tests
+                   --- tools
+                   --- variants
+                   --- platform.txt
+                   --- programmers.txt
+                   --- README.md
+                   --- boards.txt
+                   --- LICENSE
+
+-  Download binary tools
+
+   .. code:: bash
+
+       cd esp8266/tools
+       python get.py
+
+-  Restart Arduino
+
+- If using the Arduino IDE for Visual Studio (https://www.visualmicro.com/), be sure to click Tools - Visual Micro - Rescan Toolchains and Libraries 
+
+-  When later updating your local library, goto the esp8266 directory and do a git pull
+
+   .. code:: bash
+
+       cd %USERPROFILE%\Documents\hardware\esp8266com\esp8266
+       git status
+       git pull
+
+Note that you could, in theory install in ``C:\Program Files (x86)\Arduino\hardware`` however this has security implications, not to mention the directory often gets blown away when re-installing Arduino IDE. It does have the benefit (or drawback, depending on your perspective) - of being available to all users on your PC that use Arduino.
+
+
+Instructions - Other OS
 ~~~~~~~~~~~~
 
 -  Open the console and go to Arduino directory. This can be either your