Added execution steps in P.R. template

[kirinain]

Description 📖

Have added the "execution steps" part in P.R. template.

Fixes #60

Type of change 📜

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

[kirinain]

Its not specified in which branch we have to make changes, as we can't directly do it in main branch but will further have to inculcate it in the contribution section.

[topguns837]

Please inculcate these feedbacks:

• [x] Please open a Github Issue regarding this and link it to this P.R. Itself. This helps us in tracking down project progress and helps in managing workflows.

• [x] Please add a detailed description of the issue, alongwith a suitable title. I am not able to understand what this P.R. is about right now. You can take inspiration from here : https://github.com/atom-robotics-lab/ros-perception-pipeline/pull/68

Thank you for your time and effort. Please reach out to me if you need any help !

[kirinain]

@topguns837 I have made the required changes and have opened a new issue #71