Add recommended extensions to .vscode

[erikguntner]

Overview

Add a .vscode folder to the root of the repository to provide some suggested extensions that work with our codebase.

Current list of recommendations:

• ESLint - Integrates ESLint into editor
• Prettier - Code formatting for app
• Pretty Typescript Errors - Makes for more readable Typescript errors
• SQLite - Explore and query SQLite databases

Others to consider:

• Flask8 - code formatting for Python

[sanya301]

@erikguntner could you help add the role, feature and milestone here

[tylerthome]

labels updated and added to MVP -- note this does not pertain to application source code changes, nor infrastructure/testing/etc, it is a requirement for developer and admin experience (e.g. to avoid large diffs due to pre-configured style preferences in contributors' editors)