Documentation for configuring OpenCTI connector

[antoinemzs]

• Document configuration keys
  In: https://docs.openbas.io/latest/deployment/configuration/#xtm-suite

• Document automated security posture from OpenCTI report:

Explain how to enrich the OpenCTI report with a security coverage assessment; link with configuraton section
Give some examples

in https://docs.openbas.io/latest/usage/evaluate/overview/