ci: add badges for security scans (#3288)

* ci: add badges for security scans

Signed-off-by: Shahar Harari <shahar.harari@sap.com>

* change trivy workflow name to upper-case

Signed-off-by: Shahar Harari <shahar.harari@sap.com>

* trivy -> Trivy

Signed-off-by: Shahar Harari <shahar.harari@sap.com>

---------

Signed-off-by: Shahar Harari <shahar.harari@sap.com>

.github/workflows/trivy.yml

@@ -1,4 +1,4 @@
-name: trivy
+name: Trivy
 
 on:
   push:

README.md

@@ -3,6 +3,9 @@
 [![OpenSSF Scorecard](https://api.securityscorecards.dev/projects/github.com/envoyproxy/gateway/badge)](https://securityscorecards.dev/viewer/?uri=github.com/envoyproxy/gateway)
 [![Build and Test](https://github.com/envoyproxy/gateway/actions/workflows/build_and_test.yaml/badge.svg)](https://github.com/envoyproxy/gateway/actions/workflows/build_and_test.yaml)
 [![codecov](https://codecov.io/gh/envoyproxy/gateway/branch/main/graph/badge.svg)](https://codecov.io/gh/envoyproxy/gateway)
+[![CodeQL](https://github.com/envoyproxy/gateway/actions/workflows/codeql.yml/badge.svg)](https://github.com/envoyproxy/gateway/actions/workflows/codeql.yml)
+[![OSV-Scanner](https://github.com/envoyproxy/gateway/actions/workflows/osv-scanner.yml/badge.svg)](https://github.com/envoyproxy/gateway/actions/workflows/osv-scanner.yml)
+[![Trivy](https://github.com/envoyproxy/gateway/actions/workflows/trivy.yml/badge.svg)](https://github.com/envoyproxy/gateway/actions/workflows/trivy.yml)
 
 Envoy Gateway is an open source project for managing Envoy Proxy as a standalone or
 Kubernetes-based application gateway.