Add ESLint to a component

1. Add required dependencies to package.json (eslint and eslint-config-fliplet) https://github.com/Fliplet/fliplet-widget-form-builder/blob/af777d2efbe6320d7ec3f79bcc2592a21782c80d/package.json
2. Add .eslintrc file with relevant settings https://github.com/Fliplet/fliplet-widget-form-builder/blob/af777d2efbe6320d7ec3f79bcc2592a21782c80d/.eslintrc
3. Check what files to ignore in .eslintignore https://github.com/Fliplet/fliplet-widget-form-builder/blob/af777d2efbe6320d7ec3f79bcc2592a21782c80d/.eslintignore
4. Run eslint from your machine to automatically fix all errors on all files of the repo (eslint . --fix)
5. Add required globals on each file or globally on .eslintrc https://github.com/Fliplet/fliplet-widget-form-builder/blob/af777d2efbe6320d7ec3f79bcc2592a21782c80d/package.json
6. Configure your IDE to automatically fix errors on save

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Integrate with GitHub workflow

1. Add workflow file https://github.com/Fliplet/fliplet-widget-form-builder/blob/af777d2efbe6320d7ec3f79bcc2592a21782c80d/.github/workflows/main.yml
2. Amend package.json to link the script https://github.com/Fliplet/fliplet-widget-form-builder/blob/af777d2efbe6320d7ec3f79bcc2592a21782c80d/package.json#L7
3. Make sure dependencies in package.json are up to date https://github.com/Fliplet/fliplet-widget-form-builder/blob/af777d2efbe6320d7ec3f79bcc2592a21782c80d/package.json#L20-L21
4. Make sure the package-lock.json file is committed too

Once set up, each commit will trigger a build which creates annotations for all problems found, e.g. https://github.com/Fliplet/fliplet-widget-form-builder/actions/runs/378678895