[Simple/WIP] ZLLL Lanzhou Zhongchuan Internaional Airport

This add-on features a simple rendition of Lanzhou Zhongchuan International Airport (ZLLL) for Microsoft Flight Simulator. Currently a work-in-progress, it includes all parking areas but leaves taxiways to be completed. The airport utilizes a terminal 3D model sourced from cgmodel, acknowledged to have limited visual fidelity up close. Future updates aim to enhance the airports functionality and visual quality, aligning with the "simple" standard of scenery design.