missed information on the steps while and after forking

Signed-off-by: escaleira <[email protected]>

README.md

@@ -9,7 +9,9 @@ You can observe the several steps in the workshop diagram [[+]](workshop_steps.p
 
 ### Execution options 💻
 - Linux or macOS terminal (you can use the subject's virtual machine, it already has all the necessary tools installed)
-- Or Fork repo and use GitHub Actions 
+- Or Fork repo and use GitHub Actions
+    - When forking, don't forget to uncheck the option `Copy the main branch only`. You need to fork all existing branches.
+    - You will need to activate the issues (Settings -> General -> Issues)
 
 ### Workshop steps preview
 You can observe all the execution steps on GitHub [actions](https://github.com/detiuaveiro/secure-git-workshop/actions/runs/2366114917) or in the workflow definition file called [ci-demo.yml](https://github.com/detiuaveiro/secure-git-workshop/blob/ci-demo/.github/workflows/ci-demo.yml).