Refactor docs about contributions to CONTRIBUTING.md.

Per the review comments.

README.md

@@ -114,35 +114,9 @@ package (as described below):
   * Mac OS X v10.4 Tiger or newer
   * Xcode Developer Tools
 
-### Requirements for Contributors ###
+## Contributing change
 
-We welcome patches.  If you plan to contribute a patch, you need to
-build Google Test and its own tests from a git checkout (described
-below), which has further requirements:
-
-  * [Python](https://www.python.org/) v2.3 or newer (for running some of
-    the tests and re-generating certain source files from templates)
-  * [CMake](https://cmake.org/) v2.6.4 or newer
-
-## Regenerating Source Files ##
-
-Some of Google Test's source files are generated from templates (not
-in the C++ sense) using a script.
-For example, the
-file include/gtest/internal/gtest-type-util.h.pump is used to generate
-gtest-type-util.h in the same directory.
-
-You don't need to worry about regenerating the source files
-unless you need to modify them.  You would then modify the
-corresponding `.pump` files and run the '[pump.py](googletest/scripts/pump.py)'
-generator script.  See the [Pump Manual](googletest/docs/PumpManual.md).
-
-### Contributing Code ###
-
-We welcome patches.  Please read the
-[Developer's Guide](googletest/docs/DevGuide.md)
-for how you can contribute. In particular, make sure you have signed
-the Contributor License Agreement, or we won't be able to accept the
-patch.
+Please read the [`CONTRIBUTING.md`](CONTRIBUTING.md) for details on
+how to contribute to this project.
 
 Happy testing!