Docs improvements

[jmini]

• Fix whitespaces in advanced.adoc to fix the list display and the split between sentenses
• Improve the form section in advanced.adoc to make it more clear what is built-in and what is a specific file that need to be created
• In concepts.adoc Update to web-dependency-locator instead of quarkus-webjars-locator that no longer exists and use mvnpm instead of webjars.
• Improve the readme generated by the starter code to indicate where to click when the example app is started (similar to https://github.com/quarkiverse/quarkus-qute-web/pull/111 and https://github.com/quarkiverse/quarkus-web-bundler/pull/264)