Add Project Owner responsibilities

While working through the CNCF Sandbox on-boarding process, the Open
Governance checklist from opengovernance.dev recommended by CNCF
highlighted these as gaps in our current governance.

This specifies that Project Owners have responsibility for security
disclosures, Code of Conduct violations, and funds. These
responsibilities should be given to dedicated groups as the Submariner
community grows.

Also specify how Project Owners can be removed.

Signed-off-by: Daniel Farrell <dfarrell@redhat.com>

src/content/community/contributor-roles/_index.en.md

@@ -16,6 +16,8 @@ relevant to our structure or possible with our tooling:**
 * **We hope to eventually move to Kubernetes OWNERS and Prow, but until we do so we
   can't support advanced role-based automation (reviewers vs approvers;
   PR workflow commands like /okay-to-test, /lgtm, /approved).**
+* **Project Owners are given responsibility for some tasks that are handled by dedicated teams in Kubernetes (security responses, Code of
+  Conduct violations, and managing project funds). Submariner aspires to create dedicated teams for these tasks as the community grows.
 
 ---
 
@@ -179,6 +181,8 @@ The following apply to people who would be an owner:
   * Identifying subtle or complex issues in designs and implementation PRs
 * Directly contributed to the project through implementation and / or review
 
+Project Owners can be removed by stepping down or by two thirds vote of Project Owners.
+
 ### Owner Responsibilities and Privileges
 
 The following apply to people who would be an owner:
@@ -193,6 +197,9 @@ The following apply to people who would be an owner:
 * Ensure a healthy process for discussion and decision making is in place
 * Work with other project owners to maintain the project's overall health and
   success holistically
+* Receive security disclosures and ensure an adequate response.
+* Receive reports of Code of Conduct violations and ensure an adequate response.
+* Decide how funds raised by the project are spent.
 
 [parent process]: https://github.com/kubernetes/community/blob/7d2ebad43cde06607cde3d55e9eed4bb08a286a9/community-membership.md
 [code reviews]: ../../development/code-review