Update docker command to delete container on exit (#53)

Author: lcd1232

README.md

@@ -114,11 +114,11 @@ The following will work:
 ### Docker
 In the folder where your go.mod lives run
 ```
-go list -u -m -json all | docker run -i psampaz/go-mod-outdated
+go list -u -m -json all | docker run --rm -i psampaz/go-mod-outdated
 ```
 To use parameters just append
 ```
-go list -u -m -json all | docker run -i psampaz/go-mod-outdated -update
+go list -u -m -json all | docker run --rm -i psampaz/go-mod-outdated -update
 ```
 ### CI pipelines