Added a package-info for the int-specialized package.

src/main/java/pythagoras/i/package-info.java

@@ -0,0 +1,7 @@
+/**
+ * The Pythagoras geometry utility classes specialized on {@code int}. Note that many of the
+ * classes offered by the float- and double-specialized classes do not exist here. The
+ * int-specialized code supports only points, dimensions and rectangles. If you intend to use
+ * non-rectangular geometric shapes, you almost certainly want to be using floating-point math.
+ */
+package pythagoras.i;