feature/115_how_to_select_detections_by_index

[SkalskiP]

Description

This PR extends the Detections API to allow selection in several new ways. PR implements the scope of work described in #115 issue.

import supervision as sv

detections = sv.Detections(...)

# select detections by index
first_detection = detections[0]

# select detections by list or array of indexes
few_detections = detections[[0, 2, 4]]

# select detections by index slice
first_detections = detections[:2]

Type of change

• New feature (non-breaking change which adds functionality)
• This change requires a documentation update

How has this change been tested?

More unit tests.

Docs

• Docs updated? What were the changes: