Frame for micro brushed 8520

This is a lightweight and simple frame for a micro brushed quadcopter. Designed for the Eachine [AIOF3 with integrated OSD](https://www.banggood.com/Eachine-AIOF3_BRUSHED-Flight-Control-Board-Built-in-OSD-FrskyFlyskyDSM2DSMX-Receiver-Betaflight-p-1107427.html?rmmds=search) and an aio camera/transmitter combo such as Eachine [TX03](https://www.banggood.com/Eachine-TX03-Super-Mini-025mW50mW200mW-Switchable-AIO-5_8G-72CH-VTX-600TVL-13-Cmos-FPV-Camera-p-1104884.html?rmmds=search&cur_warehouse=CN) or