Added a brief version of README in markdown for Github users.

Now that we have CONTRIBUTING.md there doesn't seem to be any reason for not
having README.md as well.

Perhaps this one will replace docs/readme.txt in the future.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@76692 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

README.md

@@ -0,0 +1,62 @@
+About
+-----
+
+wxWidgets is a free and open source cross-platform C++ framework
+for writing advanced GUI applications using native controls.
+
+![wxWidgets Logo](http://www.wxwidgets.org/assets/img/header-logo.png)
+
+
+wxWidgets allows you to write native-looking GUI applications for
+all the major desktop platforms and also helps with abstracting
+the differences in the non-GUI aspects between them. It is free
+for the use in both open source and commercial applications, comes
+with the full, easy to read and modify, source and extensive
+documentation and a collection of more than a hundred examples.
+You can learn more about wxWidgets at http://www.wxwidgets.org/
+and read its documentation online at http://docs.wxwidgets.org/
+
+
+Platforms
+---------
+
+wxWidgets currently supports the following primary platforms:
+
+- Windows XP, Vista, 7 and 8 (32/64 bits).
+- Most Unix variants using the GTK+ toolkit (version 2.6 or newer or 3.x).
+- Mac OS X (10.6 or newer) using Cocoa (32/64 bits) or Carbon (32 only).
+
+Most popular C++ compilers are supported including but not limited to:
+
+- Microsoft Visual C++ 2003 or later (up to 2013).
+- g++ 3.4 or later, including MinGW/MinGW-64/TDM under Windows.
+- Clang under OS X and Linux.
+- Intel icc compiler.
+- Oracle (ex-Sun) aCC.
+
+
+Licence
+-------
+
+[wxWidgets licence](https://github.com/wxWidgets/wxWidgets/blob/master/docs/licence.txt)
+is a modified version of LGPL explicitly allowing not distributing the sources
+of an application using the library even in the case of static linking.
+
+
+Further information
+-------------------
+
+If you are looking for support, you can get it from
+
+- wx-users [mailing list](http://www.wxwidgets.org/support/mailing-lists/)
+- wxForum at http://forums.wxwidgets.org/
+- #wxwidgets IRC channel
+- http://stackoverflow.com/ if you tag your question with "wxwidgets"
+- Please report bugs at http://trac.wxwidgets.org/newticket
+
+We would also gladly welcome [your contributions](CONTRIBUTING.md).
+
+
+Have fun!
+
+The wxWidgets Team.