chore: correct the Helm image path in helm.md (#240)

Author: LinuxSuRen

docs/helm.md

@@ -1,13 +1,16 @@
-You could install api-testing via Helm chart:
+You could install `api-testing` via Helm chart:
 
 ```shell
-helm install atest oci://registry-1.docker.io/surenpi/api-testing \
-    --version v0.0.2 \
+helm install atest oci://docker.io/linuxsuren/api-testing \
+    --version v0.0.1-helm \
     --set service.type=NodePort
 ```
 
 or upgrade it:
 
 ```shell
-helm upgrade atest oci://registry-1.docker.io/surenpi/api-testing --version v0.0.3
+helm upgrade atest oci://docker.io/surenpi/api-testing \
+    --version v0.0.1-helm \
+    --set image.tag=master \
+    --set replicaCount=3
 ```