chore: Improve metadata about Flutter in Action by Eric Windmill (E…

…bookFoundation#6810)

* use top most parent url

* fix: missing title-author delimiter

* add resource format metadata

* add Maning requirements about online reading

books/free-programming-books-langs.md

@@ -731,7 +731,7 @@ That section got so big, we decided to split it into its own file, the [BY SUBJE
 ### Flutter
 
 * [Cookbook](https://flutter.dev/docs/cookbook)
-* [Flutter in Action](https://livebook.manning.com/book/flutter-in-action/welcome/v-9/) Eric Windmill 
+* [Flutter in Action](https://livebook.manning.com/book/flutter-in-action/) - Eric Windmill (HTML) *(email address requested, not required)*
 * [Flutter Succinctly, Syncfusion](https://www.syncfusion.com/ebooks/flutter-succinctly) (PDF, Kindle) (email address *requested*, not required)
 * [Flutter Tutorial](https://www.tutorialspoint.com/flutter) - Tutorials Point
 * [Flutter Tutorials Handbook](https://kodestat.gitbook.io/flutter)