Add zot as a supported registry (#2920)

Signed-off-by: Ramkumar Chinchani <rchincha@cisco.com>

README.md

@@ -306,6 +306,7 @@ Today, `cosign` has been tested and works against the following registries:
 * Elastic Container Registry
 * IBM Cloud Container Registry
 * Cloudsmith Container Registry
+* The CNCF zot Registry
 
 We aim for wide registry support. To `sign` images in registries which do not yet fully support [OCI media types](https://github.com/sigstore/cosign/blob/main/SPEC.md#object-types), one may need to use `COSIGN_DOCKER_MEDIA_TYPES` to fall back to legacy equivalents. For example:
 
@@ -750,4 +751,4 @@ process](https://github.com/sigstore/.github/blob/main/SECURITY.md)
 
 The GitHub release assets for cosign contain a PEM file produced by [GoReleaser](https://github.com/sigstore/cosign/blob/ac999344eb381ae91455b0a9c5c267e747608d76/.goreleaser.yml#L166) while signing the cosign blob that is used to verify the integrity of the release binaries. This file is not used by cosign itself, but is provided for users who wish to verify the integrity of the release binaries. 
 
-By default, cosign output these PEM files in [base64 encoded format](https://github.com/sigstore/cosign/blob/main/doc/cosign_sign-blob.md#options), this approach might be good for air-gapped environments where the PEM file is stored in a file system. So, you should decode these PEM files before using them to verify the blobs.
+By default, cosign output these PEM files in [base64 encoded format](https://github.com/sigstore/cosign/blob/main/doc/cosign_sign-blob.md#options), this approach might be good for air-gapped environments where the PEM file is stored in a file system. So, you should decode these PEM files before using them to verify the blobs.