Update Contribution guide to point to RFC process

The doc still directs people to open an epic or story on JIRA to
propose new features. This change directs people to use the RFC
process instead.

Signed-off-by: Arnaud J Le Hors <[email protected]>

docs/source/CONTRIBUTING.rst

@@ -163,28 +163,12 @@ See `releases <https://github.com/hyperledger/fabric#releases>`__ for more detai
 Making Feature/Enhancement Proposals
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
-First, take time to review
-`JIRA <https://jira.hyperledger.org/issues/?filter=12524>`__
-to be sure that there isn't already an open (or recently closed) proposal for the
-same function. If there isn't, to make a proposal we recommend that you open a
-JIRA Epic or Story, whichever seems to best fit the circumstance and
-link or inline a "one pager" of the proposal that states what the feature would
-do and, if possible, how it might be implemented. It would help also to make a
-case for why the feature should be added, such as identifying specific use
-case(s) for which the feature is needed and a case for what the benefit would be
-should the feature be implemented. Once the JIRA issue is created, and the
-"one pager" either attached, inlined in the description field, or a link to a
-publicly accessible document is added to the description, send an introductory
-email to the [email protected] mailing list linking the
-JIRA issue, and soliciting feedback.
-
-Discussion of the proposed feature should be conducted in the JIRA issue itself,
-so that we have a consistent pattern within our community as to where to find
-design discussion.
-
-Getting the support of three or more of the Hyperledger Fabric maintainers for
-the new feature will greatly enhance the probability that the feature's related
-PRs will be included in a subsequent release.
+Minor improvements can be implemented and reviewed via the normal `GitHub pull request workflow <https://guides.github.com/introduction/flow/>`__ but for changes that are more substantial Fabric follows the RFC (request for comments) process.
+
+This process is intended to provide a consistent and controlled path for major changes to Fabric and other official project components, so that all stakeholders can be confident about the direction in which Fabric is evolving.
+
+To propose a new feature, first, check
+`JIRA <https://jira.hyperledger.org/projects/FAB/issues>`__ and the `Fabric RFC repository <https://github.com/hyperledger/fabric-rfcs/>`__ to be sure that there isn't already an open (or recently closed) proposal for the same functionality. If there isn't, follow `the RFC process <https://github.com/hyperledger/fabric-rfcs/blob/master/README.md>`__ to make a proposal.
 
 Contributor meeting
 ~~~~~~~~~~~~~~~~~~~