Update 4 main ops for paths and .run() (#3715)

* Add yolov5/ to path

* rename functions to run()

* cleanup

* rename fix

* CI fix

* cleanup find models/export.py

.github/workflows/ci-testing.yml

@@ -74,5 +74,5 @@ jobs:
 
           python hubconf.py  # hub
           python models/yolo.py --cfg ${{ matrix.model }}.yaml  # inspect
-          python models/export.py --img 128 --batch 1 --weights ${{ matrix.model }}.pt  # export
+          python export.py --img 128 --batch 1 --weights ${{ matrix.model }}.pt  # export
         shell: bash