Layering and PDOM order bug fixes, add notes and lint rule about mutating accessibleOrder, https://github.com/phetsims/ratio-and-proportion/issues/72
Layering and PDOM order bug fixes, add notes and lint rule about mutating accessibleOrder, https://github.com/phetsims/ratio-and-proportion/issues/72

phetsims/scenery,phetsims/scenery,phetsims/scenery