Document how to run E2E tests locally

[Kocal]

• pnpm install
• apps/e2e & SYMFONY_REQUIRE env var
• commands:
  • per package: pnpm exec playwright test --ui
  • per package: pnpm run test:browser with all the mecanism from test_package.sh to test an UX package when it has || constraint versions
  • globally with pnpm run test:browser

[raphael-geffroy]

@Kocal Didn't understand the "per package: pnpm run test:browser with all the mecanism from test_package.sh to test an UX package when it has || constraint versions" could you explain and/or give examples ?

[Kocal]

When being under src/*/assets and run pnpm run test:browser, it will execute the script <root>/test_package.sh, which is responsible to execute Playwright for each dependency with different major version (e.g.: "chart.js": "^3.4.1 || ^4.0" for UX Chartjs).