feat: prefix shim flag names (#18)

README.md

@@ -93,7 +93,7 @@ runs:
   using: docker
   image: docker://ghcr.io/joshdk/actions-docker-shim:v0.0.2
 +  args:
-+    - --image-tag=snapshot
++    - --shim-image-tag=snapshot
 ```
 
 If your image isn't named the same as your action repository, that can be overridden as well.
@@ -103,8 +103,8 @@ runs:
   using: docker
   image: docker://ghcr.io/joshdk/actions-docker-shim:v0.0.2
   args:
-    - --image-tag=snapshot
-+    - --image=example/some-other-image
+    - --shim-image-tag=snapshot
++    - --shim-image=example/some-other-image
 ```
 
 ### Authentication
@@ -125,7 +125,7 @@ runs:
   using: docker
   image: docker://ghcr.io/joshdk/actions-docker-shim:v0.0.2
 +  args:
-+    - --token-env=INPUT_CUSTOM-TOKEN
++    - --shim-token-env=INPUT_CUSTOM-TOKEN
 ```
 
 ## License

main.go

@@ -25,11 +25,11 @@ func main() {
 //nolint:forbidigo,wsl
 func mainCmd() error {
 	var imageRepo string
-	flag.StringVar(&imageRepo, "image", "", "ghcr.io image to run")
+	flag.StringVar(&imageRepo, "shim-image", "", "ghcr.io image to run")
 	var imageTag string
-	flag.StringVar(&imageTag, "image-tag", "", "ghcr.io image tag to run")
+	flag.StringVar(&imageTag, "shim-image-tag", "", "ghcr.io image tag to run")
 	var tokenEnv string
-	flag.StringVar(&tokenEnv, "token-env", "", "env var to use for github token")
+	flag.StringVar(&tokenEnv, "shim-token-env", "", "env var to use for github token")
 	flag.Parse()
 
 	if imageRepo == "" {