COCO Training: nano and small weights release

VajraV1-nano-det and VajraV1-small-det COCO trained weights released.

• VajraV1-nano-det achieved 41.2% mAP50-95
• VajraV1-small-det achieved 47.7% mAP50-95

Initial Release (VisDrone weights)

Release 1.0.0 (Initial Release)

VajraV1 VisDrone weights released for 640 x 640 training