docs: Cross link the two types of contirbuting docs. (#2143)

* docs: Cross link the two types of contirbuting docs.

The verbose docs can be really useful if you need a lot of hand holding and details
but the quick docs are a better entrypoint for most people getting started if we
don't want to overwhelm them.

Cross link the two docs so that people can jump back and forth as it makes
sense for them.

---------

Co-authored-by: Feanil Patel <feanil@axim.org>
Co-authored-by: Ned Batchelder <ned@edx.org>

en_us/developers/source/process/overview.rst

@@ -2,7 +2,11 @@
 Process for Contributing Code
 *****************************
 
-Open edX is a massive project, and we would love you to help us build
+.. tip::
+
+   Looking for fewer words? Check out the `concise contributing guide <https://openedx.atlassian.net/wiki/spaces/COMM/pages/941457737/How+to+Start+Contributing+Code>`_.
+
+The Open edX project is massive, and we would love you to help us build
 the best online education system in the world -- we can't do it alone!
 However, the core committers on the project are also developing features
 and creating pull requests, so we need to balance reviewing time with