Prepare the project to have UI

[valiafetisov]

Goal

The project displays a basic page with the project name and a link to the playground

Context

We eventually want to have basic UI for user sign in and token generation, show documentation and graphql/sql playgrounds.
But I also assume that we want to keep API codebase independent from the UI and keep it optional / modular. So we either need to create a separate frontend repo or turn this repo into monorepo. We also need to setup a project to work with modern frontend components (eg vue).

Tasks

• Propose concrete solution
• Change structure of the project to be suitable for the frontend
• Setup frontend
• Setup proxy/middleware to serve both UI, API and playground
• Make sure the readmes are updated accordingly
• Make sure the goal is reached