[snowpatch] [PATCH] docs: add new contribution guidelines document

[Andrew Donnellan]

Add CONTRIBUTING.md, a document containing guidelines for contributions to
snowpatch. Remove existing info from README.md and replace with a link to
the new guidelines.

GitHub automatically links to this document when submitting pull
requests, so it's useful for advising people that we prefer emailed
patches.

Closes: #9 ("Add contributing document")
Suggested-by: Joel Stanley <joel at jms.id.au>
Signed-off-by: Andrew Donnellan <andrew.donnellan at au1.ibm.com>
---
 CONTRIBUTING.md | 47 +++++++++++++++++++++++++++++++++++++++++++++++
 README.md       | 14 ++------------
 2 files changed, 49 insertions(+), 12 deletions(-)
 create mode 100644 CONTRIBUTING.md

diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
new file mode 100644
index 0000000..b9b15e9
--- /dev/null
+++ b/CONTRIBUTING.md
@@ -0,0 +1,47 @@
+snowpatch contribution guidelines
+=================================
+
+Contributions should be sent as patches to the mailing list
+([snowpatch at lists.ozlabs.org](mailto:snowpatch at lists.ozlabs.org)),
+preferably using `git send-email`. We strongly prefer emailed patches
+over GitHub pull requests - after all, emailed patches are exactly why
+snowpatch exists!
+
+All commit messages must include a `Signed-off-by:` line including
+your real name, indicating that you have read and agree to the
+[Developer Certificate of Origin
+v1.1](http://developercertificate.org).
+
+Please read the Linux kernel
+[SubmittingPatches](https://www.kernel.org/doc/Documentation/SubmittingPatches)
+guidance before contributing. While many of the rules in there
+obviously aren't relevant to snowpatch, a lot of the guidance is
+relevant. Specifically, pay attention to:
+
+ * Descriptive commit messages
+ * Separating logical changes into separate patches
+ * Plain-text patches, as generated by `git send-email`
+
+We like to follow the [Rust Guidelines](https://aturon.github.io/)
+where possible - patches to fix existing non-compliant code are
+welcome!
+
+When your patch involves creating a new file, where possible please
+use a header along the lines of:
+
+```
+#
+# snowpatch - continuous integration for patch-based workflows
+#
+# Copyright (C) [YEAR] [COPYRIGHT HOLDER]
+# Authors:
+#     [AUTHOR NAME] <[AUTHOR EMAIL]>
+#
+# This program is free software; you can redistribute it and/or modify it
+# under the terms of the GNU General Public License as published by the Free
+# Software Foundation; either version 2 of the License, or (at your option)
+# any later version.
+#
+# [FILENAME] - [DESCRIPTION]
+#
+```
\ No newline at end of file
diff --git a/README.md b/README.md
index 849859b..41a416f 100644
--- a/README.md
+++ b/README.md
@@ -41,18 +41,8 @@ snowpatch can be compiled with `cargo build --release`, which will make
 Contributing
 ------------
 
-Contributions should be sent as patches to the mailing list (see
-Contact below), using `git send-email`.
-
-All commit messages must include a Signed-off-by: line, indicating
-that you have read and agree to the
-[Developer Certificate of Origin v1.1](http://developercertificate.org).
-
-Please read the Linux kernel
-[SubmittingPatches](https://www.kernel.org/doc/Documentation/SubmittingPatches)
-guidance before contributing. While many of the rules in there
-obviously aren't relevant to snowpatch, a lot of the guidance is
-relevant.
+Please read our [contribution guidelines](CONTRIBUTING.md) for more
+information about contributing.
 
 
 Contact
-- 
Andrew Donnellan              Software Engineer, OzLabs
andrew.donnellan at au1.ibm.com  Australia Development Lab, Canberra
+61 2 6201 8874 (work)        IBM Australia Limited