feat: added .env.example file to template secret variables

[harshitsaini17]

Title

Added .env.example file to template secret variables

Type of Change

• New feature
• Bug fix
• UI/UX improvement

fix: #94

Checklist

• My code adheres to the coding and style guidelines of the project.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• My changes generate no new warnings.

Description and Impact

1. I modify the folder structure of the project
2. I added .env.example for the example secret variables
3. I remove all the warnings so that it can build successfully