Update contributing and readme files [skip ci]

Author: leezer3

Contributing.md

@@ -11,8 +11,21 @@ This file is a work in progress, and is intended to serve as a general set of gu
 
 #### Code Licencing
 
-The basic licence for openBVE is Public Domain.
-Please only contribute code which is licenced under either Public Domain, or loose permissive licences (e.g. BSD-2 and compatible)
+The original codebase for OpenBVE is licenced under the public domain. (Please see https://github.com/leezer3/OpenBVE/issues/305  for further details and discussion)
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+However, over the last 10+ years, we've found that not having a recognised OSS licence can be more of a hindrance than a help.
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+With this in mind, we've chosen to move to using the BSD-2 clause licence for newer code contributions.
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+We're also happy to accept code under similar loose, permissive licences that maintain the spirit of the original public domain aims. 
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+New code should clearly state the author and licence (if applicable) in the file header.
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+Please do not contribute code under the GPL or simiar 'viral' or restrictive licences.
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 ### Backwards Compatibility
 

Readme.md

@@ -6,7 +6,10 @@
 
 This repository contains the source code for the Train Simulator OpenBVE, a 3D cab based simulator.
 
-The simulator supports both native CSV / RW routes, and routes built for the legacy DOS based simulator Mechanik.
+The simulator supports the following route formats:
+* Native CSV / RW.
+* BVE5 TXT format.
+* Mechanik DAT format.
 
 OpenBVE is built in OpenGL, using the OpenTK framework for windowing.
 
@@ -53,7 +56,7 @@ http://bveworldwide.forumotion.com/f14-the-sim-in-time-general-discussion
 ### License
 
 The original founder of this project, Michelle intended for this program to be placed in the public domain. 
-In practice over the last 10 years I've been maintaining this, we've found that whilst public domain was a noble idea, having no recognised licence and attempting to disclaim copyright tends to produce many of it's own challenges.
+In practice over the last 10+ years I've been maintaining this, we've found that whilst public domain was a noble idea, having no recognised licence and attempting to disclaim copyright tends to produce many of it's own challenges.
 
 As a result, all new code is licenced under BSD-2 or a similar permissive licence (as appropriate)- Please see the source headers.