added manual

docs/groups.typ

@@ -0,0 +1,19 @@
+/// Creates a group of sequences
+/// #examples.grp
+/// - name (content): The group's name
+/// - desc (none, content): Optional description
+/// - type (str): The groups's type (unused for the moment)
+/// - elmts (array): Elements inside the group (can be sequences, other groups, notes, etc.)
+#let _grp(
+  name,
+  desc: none,
+  type: "default",
+  elmts
+) = {}
+
+/// Synchronizes multiple sequences
+/// #examples.sync
+/// - elmts (array): Synchronized elements (generally sequences or notes)
+#let _sync(
+  elmts
+)