Rename project files to align with new directory structure

dart/pubspec.yaml

@@ -0,0 +1,16 @@
+name: file_formats
+description: A sample command-line application with basic argument parsing.
+version: 0.0.1
+# repository: https://github.com/my_org/my_repo
+
+environment:
+  sdk: ^3.0.0
+
+# Add regular dependencies here.
+dependencies:
+  args: ^2.5.0
+  color_simp: ^1.0.3
+
+dev_dependencies:
+  lints: ^5.0.0
+  test: ^1.24.0