add image_tag variable; improve documentation

action.yaml

@@ -1,6 +1,6 @@
 name: 'Kaniko Build & Push'
-description: 'Builds a multi-stage Dockerfile using Kaniko and pushes it to a container registry'
-author: 'Your Name'
+description: 'Builds a (multi-stage) Dockerfile using Kaniko and pushes it to container registry'
+author: 'tertek'
 
 inputs:
   registry_user:
@@ -20,6 +20,10 @@ inputs:
   destination_image:
     description: 'The full image name and tag (e.g., my-repo/php-fpm:test)'
     required: true
+  image_tag:
+    description: 'Name of the image tag, appended to the image name with :latest as default'
+    required: false
+    default: 'latest'    
   cache_repo:
     description: 'Custom path for Kaniko cache layers'
     required: false
@@ -57,7 +61,7 @@ runs:
           --context="dir://${{ forgejo.workspace }}" \
           --dockerfile="${{ forgejo.workspace }}/${{ inputs.dockerfile_path }}" \
           $TARGET_ARG \
-          --destination="$REGISTRY_DOMAIN/${{ inputs.destination_image }}" \
+          --destination="$REGISTRY_DOMAIN/${{ inputs.destination_image }}:${{ inputs.image_tag }}" \
           --cache=true \
           --cache-repo="$CACHE_REPO_ARG" \
           --compressed-caching