Add initial configuration, tokens, and widgets for M3E components

- Introduced `.gitignore` and `.metadata` for apps and examples.
- Added Flutter/Dart analysis configurations (`analysis_options.yaml`).
- Implemented foundational tokens and themes for M3E (colors, shapes).
- Created base implementations for `IconButtonM3E` and `SplitButtonM3E`.
- Set up CI workflow (`ci.yaml`) to automate testing and analysis.

README.md

@@ -0,0 +1,24 @@
+# Material 3 Expressive – Flutter Monorepo (Starter)
+
+This is a starter monorepo for **Material 3 Expressive (M3E)** Flutter packages.
+
+- `packages/m3e_design` – design language core (tokens, ThemeExtension, motion)
+- `packages/m3e_collection` – re-exports all component packages
+- `packages/icon_button_m3e` – example component (uses `m3e_design`)
+- `packages/split_button_m3e` – example split button component
+- `apps/gallery` – showcase app that consumes `m3e_collection`
+
+## Quick start
+
+```bash
+dart pub global activate melos
+melos bootstrap
+
+# run the gallery
+cd apps/gallery
+flutter run
+```
+
+## Structure
+
+See `melos.yaml`, `analysis_options.yaml`, and the package-level READMEs.