Add preliminary README.md for github

Github uses a special markdown syntax and display the content of the README
formatted on the front page of the repo. This readme contains information for
github users.

README.md

@@ -0,0 +1,30 @@
+The PHP Interpreter
+===================
+
+This is the github mirror of the official PHP repository located at
+http://git.php.net.
+
+[![Build Status](https://secure.travis-ci.org/php/php-src.png?branch=master)](http://travis-ci.org/php/php-src)
+
+Pull Requests
+=============
+PHP accepts pull requests via github. Discussions are done on github, but
+depending on the topic can also be relayed to the official PHP developer
+mailinglist [email protected].
+
+New features require an RFC and must be accepted by the developers.
+See https://wiki.php.net/rfc and https://wiki.php.net/rfc/voting for more
+information on the process.
+
+Bug fixes **do not** require an RFC, but require a bugtracker ticket. Always
+open a ticket at http://bugs.php.net and reference the bug id using #NNNNNN.
+
+    Fix #55371: get_magic_quotes_gpc() throws deprecation warning
+
+    After removing magic quotes, the get_magic_quotes_gpc function caused
+    a deprecate warning. get_magic_quotes_gpc can be used to detected
+    the magic_quotes behavior and therefore should not raise a warning at any
+    time. The patch removes this warning
+
+We do not merge pull requests directly on github. All PRs will be
+pulled and pushed through http://git.php.net.