docs: fix broken link to "Support Policy" page

- use a plain relative link like the other in-repo links in this README

- also fix markdown semantics with the last heading
  - should be an `h2` since there can only be one `h1` per page and that's already the first heading of the README

README.md

@@ -26,7 +26,7 @@ These images are built using [bazel](https://bazel.build), but they can also be
 
 ### What images are available?
 
-The following images are currently published and updated by the distroless project (see [SUPPORT_POLICY](<[url](https://github.com/GoogleContainerTools/distroless/blob/main/SUPPORT_POLICY.md)>) for support timelines)
+The following images are currently published and updated by the distroless project (see [SUPPORT_POLICY.md](SUPPORT_POLICY.md) for support timelines)
 
 #### Debian 12
 
@@ -213,7 +213,7 @@ BUILD       Dockerfile  hello.py
 
 If your project uses Distroless, send a PR to add your project here!
 
-# Community Discussion
+## Community Discussion
 
 - [distroless-users Google Group](https://groups.google.com/forum/#!forum/distroless-users)
 - [Kubernetes slack #distroless channel](https://slack.k8s.io/)