Fix broken link

Author: crandmck

docs/getting-started.mdx

@@ -87,7 +87,7 @@ In practice, to use a certificate with the CAI SDK, follow this process:
 3. Use one of the supporting CAI libraries or C2PA Tool to sign manifests using the certificate and your private key.
 
 :::info
-For more information on getting and using certificates, see [Signing and certificates](signing/signing-certs.md).
+For more information on getting and using certificates, see [Signing and certificates](signing/index.md).
 :::
 
 ### Verify known certificate list