Add shared Prettier config for formatting JavaScript / TypeScript.

[junhaoliao]

Currently, our web projects (e.g. clp/components/webui, clp/components/log-viewer-webui, yscope-log-viewer) uses a shared ESLint config (i.e., eslint-config-yscope) for linting and formatting.

We should explore adding a Prettier configuration for formatting, which would allow us to disable formatting rules in eslint-config-yscope and achieve more consistent code formatting.

Reference

https://prettier.io/docs/integrating-with-linters