Improve consistency in Sourcegraph's frontend codebase

Created by: taylorsperry

Problem to solve

Quarterly DevX surveys regularly identify "codebase inconsistency" as a main contributor to poor developer experience at Sourcegraph. It makes it difficult for teams to iterate quickly, complicates the debugging process, and bloats CI/CD time.

A more consistent client codebase will:

Reduce mental overhead for engineers by standardizing file structure, naming conventions, patterns, and conventions
Make it easier to find, implement, and update reusable components
Enable us to automate wide-ranging changes and migrate technologies quickly
Empower teammates to work outside their domain area (and jump into new ones)
Improve onboarding so that new teammates can have an impact faster

Measure of success

There's one answer to every question: Codebase conventions are documented in the handbook, as is the long-term vision for our tech stack, tooling, and libraries.
All major ongoing migrations are complete.
We see fewer comments about codebase complexity in the quarterly DevX surveys.

Solution summary

Define React component file structure, naming conventions, and organization for reusable modules.
Track and complete ongoing migrations, improve tooling for future migrations, and identify next priority migrations
Set up linters and component generators that enforce consistency

Artifacts:

What specific customers are we iterating on the problem and solution with?

Internal Sourcegraph developers

Impact on use cases

Delivery plan

TODO