skip apple pencil first n samples to overcome the initial pressure spike

src/canvas_modes.h

@@ -38,7 +38,7 @@ public:
 
 class CanvasModePen : public CanvasMode
 {
-    bool m_touching = true;
+    bool m_draw_tip = false;
     bool m_dragging = false;
     glm::vec2 m_pan_start;
     glm::vec2 m_cur_pos;