1.  flutt
    1.1.  commands run in terminal
        >>
        flutter pub add flutter_riverpod
        flutter pub add riverpod_annotation
        flutter pub add dev:riverpod_generator
        flutter pub add dev:build_runner
        flutter pub add dev:custom_lint
        flutter pub add dev:riverpod_lint
        <<
    1.2.
       >>
       flutter pub get
       flutter pub run build_runner build ( instead of flutter pub run build_runner watch)
       <<
    1.3.  Add Links.txt file.
    1.4.  Checkout in other station ==> Must re run 1.1. steps again. (I don't Know why)
        (Re-run can update dependencies)
    1.5. Update analysis_options.yaml, then run
         >>
           dart run custom_lint
         <<
    1.6. Add a "hello world" sample to "main_hello_riverpod.dart", we have some error in code.
         Now run
         >>
         flutter pub run build_runner build
         <<
         to generate some files (include main_hello_riverpod.g.dart).
         Then fix "main_hello_riverpod.dart" with (main.g.dart --> main_hello_riverpod.g.dart).