Move and update Mikes MFA example to demos

@mikeeddington created an example for getting an MFA token for DAST using selenium. A customer has requested an example for doing this with DAST API.

• Mikes example project: https://gitlab.com/mikeeddington/selenium-with-dast

1. Create a demo example for DAST based on Mike's example project
2. Create a demo example for DAST API & API Fuzzing based on Mike's example project, using overrides script.
3. Link to demos from documentation (DAST, DAST API, API Fuzzing)
   1. DAST
   2. DAST API
   3. API Fuzzing