This PR is the initial documentation structure including the basic information about the project and Sphinx configuration.

####CONTENTS:
- Getting Started
- Installing
- Boards
- Libraries
- Library Builder
- Tutorials
- ESP-IDF as Component
- OTA Web Update
- makeEspArduino
- Troubleshooting
- Contributing

This PR also changes the README.md.

Board images updated and added warning on Flash/PSRAM pins

* Updated Readme.md

Added links to latest release. Made it look a lot cleaner.

* Update README.md

Add download counter for releases

* Added instructions for installation with boards manager (stolen directly from esp8266)

* changed to production link instead of dev

* Added to main README. Made mods to images as requested.

* Added links for development package

* Moved version images to README.md

* Just a little change for cleaner look

* Cleaned up README.md and boards_manager.md to make installation easier.

* Added instructions for installation with boards manager (stolen directly from esp8266)

* changed to production link instead of dev

* Added to main README. Made mods to images as requested.

* Added links for development package

* Update README.md

* Create opensuse.md

* DOCUMENTATION: Moved installation instructions to separate page

* Added Fedora to contents table
* Added Issue/Bug Report section to README
* Some minor improvements

* DOCUMENTATION: Rename directory doc to docs

* Also move ISSUE_TEMPLATE.md to docs directory

* DOCUMENTATION: Use current repo's files

* This makes it consistent instead  of having few local and few pointing to
  espressif/arduino-esp32 by all linking to local files

* DOCUMENTATION: Fix hyperlink to issue/bug template in contents

* DOCUMENTATION: contents: supress platform specific installation instruction

* Add hint

* Update README.md

* Update README.md

* Update README.md

* Initial version of build script for @PlatformIO; CI integration for Linux, macOS and Windows

* Remove CI badges

Add Travis build badge

With this step we remove all dependencies, but git. Mac and Linux come
with Python by default, so they will keep using get.py to update the
toolchain and support binaries. Windows users have an "All point and
click" installation option that requires only git and Arduino to be
downloaded.
Fingers crossed :)

- get.exe is clickable and will soon download binary form of esptool,
which will really simplify installation on Windows
- get.py does not require any extra modules on Linux and Mac
- ```pip install requests``` required only on Windows (if not using
get.exe)
- Paths are made relative to the file in order to make the windows
executable clickable.

Add ```pip install requests``` to install steps

* Add brief explanation about app_main() function

* Update README.md

The proposed sentence is restated in a more clear way.

* Fix typo

Change is to not be mistaken with SD Card

Add exception decoder and fix layout

Add instructions for using as IDF component

- Link to Windows instructions
- Update instructions for Linux and Mac