minor #3086 Add doc for E2E steps + minor modifications (raphael-geffroy)

This PR was merged into the 2.x branch.

Discussion
----------

 Add doc for E2E steps + minor modifications

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| Docs?         | yes
| Issues        | Fix #3039
| License       | MIT

Commits
-------

ceefa1d8501 [Docs] Add doc for E2E steps + minor modifications

Author: Kocal

assets/package.json

@@ -25,6 +25,7 @@
         "test": "pnpm run test:unit && pnpm run test:browser",
         "test:unit": "../../../bin/test_package.sh . --unit",
         "test:browser": "../../../bin/test_package.sh . --browser",
+        "test:browser:ui": "../../../bin/test_package.sh . --browser --ui",
         "check": "biome check",
         "ci": "biome ci"
     },