Setup a local dev environment with mocked Firebase

[emettely]

Is your feature request related to a problem? Please describe.
Our local development environment currently links to an actual Firestore DB in dev environment.
Most often when developing locally, you use the env variable to determine which environment you're in. From there, you would need to replace the Firebase SDK to a mocked one.

Describe the solution you'd like

• A local dev environment that uses a mocked database instead of the live one.
• Document the process here
• Running locally reflects what would be on live
• Deploying to live reflects what was in local development

Describe alternatives you've considered

Additional context

[allishultes]

Alternative approach:

Everyone claim a project id. You are responsible for the data in your project. Please input test data (for reference check out project MHhZZHXlzvGA9c9ARkEE) and only use your project when working on an issue locally.

1. @katiaartsenkova:

• title: katia

2. @bennuttall:

• title: ben

3. @emettely:

• title: eimi

4. @allishultes:

• title: alli