style: #879 analysis_options.yaml add comments

analysis_options.yaml

@@ -2,6 +2,9 @@ include: package:flutter_lints/flutter.yaml
 
 # See https://dart-lang.github.io/linter/lints/
 
+# `dart fix --dry-run` to try fix
+# `dart fix --apply` to apply fix
+
 analyzer:
   errors:
     invalid_assignment: error
@@ -24,4 +27,3 @@ linter:
     avoid_print: true
     avoid_dynamic_calls: true
     avoid_annotating_with_dynamic: true
-    always_specify_types: true