CONTRIBUTING: Add commit guidelines
## Developer Certificate of Origin
By contributing, you agree to the Linux Foundation's Developer Certificate of Origin ([DCO](DCO)). The DCO is a statement that you, the contributor, have the legal right to make your contribution and understand the contribution will be distributed as part of this project.
+
+## Commit guidelines
+
+The title of the commit message should describe the _what_ about the
+changes. Additionally, it is helpful to add the _why_ in the body of
+the commit changes. Make sure to include any assumptions that you
+might have made in this commit. Changes to unrelated parts of the
+codebase should be kept as separate commits.
+
+### Commit Format
+
+```
+<area>: <description of changes>
+
+Detailed information about the commit message goes here
+```
+
+The title should not exceed 80 chars, although keeping it under 72
+chars is appreciated.
+
+Please wrap the body of commit message at a
+maximum of 80 chars.
+
+Here are a few example commit messages:
+
+Good:
+```
+packet/flatcar-linux: Add support for reservation_ids on workers
+
+
+```
+
+Bad:
+```
+Add support for reservation_ids on workers for packet
+```
+
+
+Acceptable:
+```
+packet: Add support for reservation_ids on workers
+```
+
+This format is acceptable as sometimes nesting parts of the codebase
+in the title can take up a lot of characters. Also at the same time,
+using `packet/flatcar-linux` is redundant in the title, unless there
+is another directory of the same name but with a different parent
+directory, for eg: `docs/packet`.
