The Missing Koiari (Kokoda Track) Bush Strips

This adds the remaining three missing bush strips in the Koiari (Kokoda Track) area: Boridi, Timkenumo, and Myola.  Fans of the old ORBX AYPY bush strips in previous sims will remember these. (Bodinumu was also missing but a nice rendition has already been created by Callsign1065 here: https://flightsim.to/file/25878/bodinumu-airstrip-bnm)