Fast/group creation gif (#676)

* Updated Readme with Group creation GIF

Added visual representation of checklist group creation.

* Update README.md

Added v1 version of group creation GIF.

* localize gif

Co-authored-by: Ludovico Magnocavallo <ludomagno@google.com>

fast/stages/00-bootstrap/README.md

@@ -177,6 +177,8 @@ Before the first run, the following IAM groups must exist to allow IAM bindings
 - gcp-security-admins
 - gcp-support
 
+You can refer to [this animated image](./groups.gif) for a step by step on group creation.
+
 #### Configure variables
 
 Then make sure you have configured the correct values for the following variables by providing a `terraform.tfvars` file: