Add API changes

mdboom · mdboom · commit 1761a03b9e25 · 2018-11-08T17:20:11.000-05:00
diff --git a/doc/api/api_changes.rst b/doc/api/api_changes.rst
@@ -44,6 +44,16 @@ subplotparams will collapse axes to zero width or height.  This prevents
 ``tight_layout`` from being executed.  Similarly
 `.tight_layout.get_tight_layout_figure` will return None.  
 
+To improve import (startup) time, private modules are now imported lazily.
+These modules are no longer available at these locations:
+
+  - `matplotlib.backends.backend_agg._png`
+  - `matplotlib.contour._contour`
+  - `matplotlib.image._png`
+  - `matplotlib.mathtext._png`
+  - `matplotlib.tri.triangulation._tri`
+  - `matplotlib.tri.triangulation._qhull`
+
 API Changes for 3.0.0
 =====================
 
