Added docs for the sample-flask-mongo-local app

[Swpn0neel]

Pull Request Template

Description

Added docs for the sample-flask-mongo-local app

Type of change

Please delete options that are not relevant.

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

How Has This Been Tested?

The build is successful

Additional Context (Please include any Screenshots/gifs if relevant)

Checklist:

• [x] My code follows the style guidelines of this project.
• [x] I have performed a self-review of my own code.
• [x] I have made corresponding changes to the documentation.
• [x] I have added corresponding tests.
• [x] Any dependent changes have been merged and published in downstream modules.