Please install the workspace recommended extensions - mainly ESLint and Prettier.
This project uses eslint configured with standard-with-typescript, which is a standard linter configuration, based on standardjs.
We use prettier to format the source code, rather than eslint. If you use a linter for code formatting then you end up with red squigglies all over the place related to code formatting, rather than code errors, which makes coding unpleasant.
The project workspace settings are set up to format the code on save. Prettier will format the code every time you save your work. It's important that code format-on-save is used by everyone, to avoid having PR's full of diffs caused by unformatted code.