git: 7f6a000fcec3 - main - CONTRIBUTING: add intro describing the ways we accept contributions

The branch main has been updated by emaste:

URL: https://cgit.FreeBSD.org/src/commit/?id=7f6a000fcec36ea8aa5c12ab1f58d4648d114003

commit 7f6a000fcec36ea8aa5c12ab1f58d4648d114003
Author:     Ed Maste <emaste@FreeBSD.org>
AuthorDate: 2023-04-27 16:13:04 +0000
Commit:     Ed Maste <emaste@FreeBSD.org>
CommitDate: 2023-04-27 23:43:56 +0000

    CONTRIBUTING: add intro describing the ways we accept contributions
    
    Reviewed by:    imp
    Sponsored by:   The FreeBSD Foundation
    Differential Revision: https://reviews.freebsd.org/D39854
---
 CONTRIBUTING.md | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 3bdcd587df24..cc86e096dd18 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -8,6 +8,16 @@ how to build different parts of the project, etc. The
 [developer's handbook](https://docs.freebsd.org/en/books/developers-handbook/)
 is another useful resource.
 
+FreeBSD accepts source code contributions using one of several methods:
+- A GitHub [pull request](https://github.com/freebsd/freebsd-src/pulls)
+- A code review in [Phabricator](https://reviews.freebsd.org/differential)
+- An attachment on a [Bugzilla ticket](https://bugs.freebsd.org)
+- Direct access to the [Git repository](https://cgit.freebsd.org/src/)
+
+The preferred method depends on a few factors including the size or scope of
+the change.  GitHub pull requests are preferred for relatively straightforward
+changes where the contributor already has a GitHub account.
+
 ## GitHub Pull Requests
 
 Presently, GitHub 'freebsd-src' repository is one of the publish-only services