feat: init Go module with config and in-memory note store

internal/store/store.go

@@ -0,0 +1,12 @@
+package store
+
+import "context"
+
+type NoteStore interface {
+	GetByID(ctx context.Context, id string) (*Note, error)
+	List(ctx context.Context) ([]*Note, error)
+	Create(ctx context.Context, note *Note) error
+	Update(ctx context.Context, note *Note) error
+	Delete(ctx context.Context, id string) error
+	SearchByKeyword(ctx context.Context, keyword string) ([]*Note, error)
+}