Add ResolveInFrameA type

Author: AbdulrhmnGhanem

src/Mechanical/MultiBody2D/types.jl

@@ -0,0 +1,10 @@
+
+@enum ResolveInFrameA begin
+    world = "Resolve in world frame"
+    frame_a = "Resolve in frame_a"
+    frame_resolve = "Resolve in frame_resolve (frame_resolve must be connected)"
+end
+
+Base.@doc """
+    Enumeration to define the frame in which an absolute vector is resolved (world, frame_a, frame_resolve)
+""" ResolveInFrameA