[PATCH hwc v1] drm_hwcomposer: Add CONTRIBUTING file

[Robert Foss]

Some basic guidelines for contributions could come in handy.

These are copied from IGT and modified to be suitable.

Signed-off-by: Robert Foss <robert.foss at collabora.com>
---
 CONTRIBUTING | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 CONTRIBUTING

diff --git a/CONTRIBUTING b/CONTRIBUTING
new file mode 100644
index 0000000..f1b4775
--- /dev/null
+++ b/CONTRIBUTING
@@ -0,0 +1,31 @@
+Patches to drm_hwcomposer are very much welcome, we really want this to be the
+universal HW composer implementation for Android and similar platforms
+So please bring on porting patches, bugfixes, improvements for documentation
+and new features.
+
+A short list of contribution guidelines:
+
+- Please submit patches formatted with git send-email/git format-patch or
+  equivalent to
+
+    dri-devel <dri-devel at lists.freedesktop.org>
+
+  Please use --subject-prefix="PATCH hwc" so that drm_hwcomposer patches are easily
+  identified in the massive amount mails on dri-devel. To ensure this is always
+  done, run:
+
+    git config format.subjectprefix "PATCH hwc"
+
+- drm_hwcomposer is Apache 2.0 Licensed and we require contributions to follow the
+  developer's certificate of origin: http://developercertificate.org/
+
+- When submitting new code please follow the naming conventions documented
+  in the generated documentation. Also please make full use of all the helpers and
+  convenience macros provided by drm_hwcomposer. The below command can help you
+  with formatting of your patches:
+  git diff | clang-format-diff-3.5 -p 1 -style=file
+
+- Harware specific changes should get tested on relevant platforms
+  before committing.
+
+Happy hacking!
-- 
2.11.0