Simplify the CONTRIBUTING.md document

Signed-off-by: Richard Wall <[email protected]>

Author: wallrj

CONTRIBUTING.md

@@ -1,64 +1,3 @@
 # Contributing
 
-You can find our full contributing guide on [our website](https://cert-manager.io/docs/contributing/).
-
-## DCO Sign off
-
-All contributors to the project retain copyright to their work. However, to ensure
-that they are only submitting work that they have rights to, we require
-everyone to acknowledge this by signing their work.
-
-Any copyright notices in this repo should specify the authors as
-"The cert-manager Authors".
-
-To sign your work, just add a line like this at the end of your commit message:
-
-```text
-Signed-off-by: Joe Bloggs <[email protected]>
-```
-
-This can easily be done with the `--signoff` option to `git commit`.
-You can also mass sign-off a whole PR with `git rebase --signoff master`, replacing
-`master` with the branch you are creating a pull request again if not master.
-
-By doing this you state that you can certify the following (from https://developercertificate.org/):
-
-```text
-Developer Certificate of Origin
-Version 1.1
-
-Copyright (C) 2004, 2006 The Linux Foundation and its contributors.
-1 Letterman Drive
-Suite D4700
-San Francisco, CA, 94129
-
-Everyone is permitted to copy and distribute verbatim copies of this
-license document, but changing it is not allowed.
-
-
-Developer's Certificate of Origin 1.1
-
-By making a contribution to this project, I certify that:
-
-(a) The contribution was created in whole or in part by me and I
-    have the right to submit it under the open source license
-    indicated in the file; or
-
-(b) The contribution is based upon previous work that, to the best
-    of my knowledge, is covered under an appropriate open source
-    license and I have the right under that license to submit that
-    work with modifications, whether created in whole or in part
-    by me, under the same open source license (unless I am
-    permitted to submit under a different license), as indicated
-    in the file; or
-
-(c) The contribution was provided directly to me by some other
-    person who certified (a), (b) or (c) and I have not modified
-    it.
-
-(d) I understand and agree that this project and the contribution
-    are public and that a record of the contribution (including all
-    personal information I submit with it, including my sign-off) is
-    maintained indefinitely and may be redistributed consistent with
-    this project or the open source license(s) involved.
-```
+Please refer to the [cert-manager Contributing guide](https://cert-manager.io/docs/contributing/).