Assigning real indices to vertices created in bmesh

When we work with the bmesh object through the Blender Python API to create new geometry, all created vertices receive an index equal to -1. Although we can fully interact and control the created vertices, the lack of a numbered index can make it somewhat difficult to perceive the geometry and debug the code.

Read more: https://b3d.interplanety.org/en/assigning-real-indices-to-vertices-created-in-bmesh/