added correct commands for steps on Creating a Docker container action page

content/actions/creating-actions/creating-a-docker-container-action.md

@@ -120,12 +120,27 @@ Next, the script gets the current time and sets it as an output variable that ac
   ```
   If `entrypoint.sh` executes without any errors, the action's status is set to `success`. You can also explicitly set exit codes in your action's code to provide an action's status. For more information, see "[Setting exit codes for actions](/actions/creating-actions/setting-exit-codes-for-actions)."
 
-1. Make your `entrypoint.sh` file executable by running the following command on your system.
+
+3. Make your `entrypoint.sh` file executable by following the below commands on your system.
+
+Git provides a way to explicitly change the permission mode of a file so that it doesn't get reset every time there is a clone/fork.
+<br>The command works as below.
 
   ```shell{:copy}
-  $ chmod +x entrypoint.sh
+  $ git update-index --chmod=+x entrypoint.sh
   ```
 
+The permission mode of the file in the git index can be checked by running following command.
+
+  ```shell{:copy}
+  $ git ls-files --stage entrypoint.sh
+  ```
+
+If you receive an output like this- <br>
+`100755 e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 0       entrypoint.sh`
+
+it means that the file has the executable permission. (Here `755` denotes the executable permission)
+
 ## Creating a README
 
 To let people know how to use your action, you can create a README file. A README is most helpful when you plan to share your action publicly, but is also a great way to remind you or your team how to use the action.