[feature] - Reporter signup

### Narrative

As an unregistered responder,
I want to create an account
so that I can begin receiving and responding to reports;

### Acceptance Criteria

- **Scenario**: Describe Scenario\
Given an unregistered responder visits the base URL of RapidMed wishing to signup,
When the **Responder** button is clicked and he/she clicks the **Signup** button,
Then he/she gets routed to the **Responder** signup page

Start at RapidMed's base URL and inspect the existing Responder button and Signup navigation. Verify the flow for an unregistered responder: selecting Responder and then Signup should reach the Responder signup page, matching the acceptance scenario.

Written by the indexing model from the issue text.