update to 3.0

docs/lib3x-pie.md

@@ -0,0 +1,20 @@
+# pie
+
+Creates a pie (circular sector). Its `$fa`, `$fs` and `$fn` are consistent with the `circle` module.
+
+## Parameters
+
+- `radius` : The radius of the circle.
+- `angle` : A single value or a 2 element vector which defines the central angle. The first element of the vector is the beginning angle in degrees, and the second element is the ending angle.
+- `$fa`, `$fs`, `$fn` : Check [the circle module](https://en.wikibooks.org/wiki/OpenSCAD_User_Manual/Using_the_2D_Subsystem#circle) for more details.
+
+## Examples
+
+    use <pie.scad>;
+
+    pie(radius = 20, angle = [210, 310]);   
+    translate([-15, 0, 0]) pie(radius = 20, angle = [45, 135]);  
+    translate([15, 0, 0]) pie(radius = 20, angle = [45, 135], $fn = 12);  
+
+![pie](images/lib3x-pie-1.JPG)
+