add doc

README.md

@@ -236,7 +236,7 @@ See [examples](examples).
 ### Voronoi
 - [voronoi/vrn2_from](https://openhome.cc/eGossip/OpenSCAD/lib2x-vrn2_from.html)
 - voronoi/vrn2_space
-- voronoi/vrn2_cells_from
+- [voronoi/vrn2_cells_from](https://openhome.cc/eGossip/OpenSCAD/lib2x-vrn2_cells_from.html)
 - voronoi/vrn2_cells_space
 - voronoi/vrn3_from
 - voronoi/vrn3_space

docs/lib2x-vrn2_cells_from.md

@@ -0,0 +1,35 @@
+# vrn2_cells_from
+
+Creats Voronoi shapes from a list of points. 
+
+**Since:** 2.4
+
+## Parameters
+
+- `points` : Points for each cell. 
+
+## Examples
+
+    use <hull_polyline2d.scad>;
+    use <voronoi/vrn2_cells_from.scad>;
+
+    xs1 = rands(-20, 20, 15);
+    ys1 = rands(-20, 20, 15);
+    points = [for(i = [0:len(xs1) - 1]) [xs1[i], ys1[i]]];
+
+    cells = vrn2_cells_from(points);
+    for(i = [0:len(points) - 1]) {
+        pt = points[i];
+        cell = cells[i];
+        
+        linear_extrude(1)
+            hull_polyline2d(concat(cell, [cell[0]]), width = 1);
+        
+        color(rands(0, 1, 3))
+        translate(pt)    
+        linear_extrude(2, scale = 0.8)
+        translate(-pt)    
+            polygon(cell);
+    }
+
+![vrn2_cells_from](images/lib2x-vrn2_cells_from-1.JPG)

src/voronoi/vrn2_cells_from.scad

@@ -1,3 +1,14 @@
+/**
+* vrn2_cells_from.scad
+*
+* @copyright Justin Lin, 2020
+* @license https://opensource.org/licenses/lgpl-3.0.html
+*
+* @see https://openhome.cc/eGossip/OpenSCAD/lib2x-vrn2_cells_from.html
+*
+**/
+
+
 use <_impl/_vrn2_cells_from_impl.scad>;
 use <_impl/_convex_intersection_for.scad>;
 use <../shape_square.scad>;