Update readme/clean up project

[shlag3n]

• 1. Update readme and make possible to setup the project just following the instructions:
• check installation steps (check Dockerfile for that, it's in use for kubernetes)
• list all env that are needed at .env.template
• describe how to to do initial db seeding at least how to create admin user, as bonus (if it's easy to do) how to get dump from server
• 2. Update readme with all necessary settings to have integration with LCMS, Canvas. Most of them are there, but some contains mistakes like name of Canvas Instance (should be public:domain not any) and some are not listed at all like Google variables (service account need to be setup under client google user and some project). Also add what necessary permissions we need for canvas user that will use this tool (check that with Whitney).
• 3. General clean-up
• set up linters
• set up autobuild - lint + test (GH Actions)
• remove some obsolete files (e.g. .blitz-console-history)
• remove stale branches (keep staging/production).
• check package.json dependencies and keep at dev dependencies only those that we need locally
• 4. Set airbrake env different from node env, smth like environment: process.env.AIRBRAKE_ENV || process.env.NODE_ENV
• 5. (If it will take like 20 min) update UI to show errors on issues with Canvas LMS