docs: add JSDoc on prompt_template.ts

[Ni-zav]

Description

added JSDoc comments and usage examples to all exported functions in prompt_templates.ts. This should improves the code readability, help contributors understand the codebase.

Type of Change

• Documentation update

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules
• I have tested the app on Mac OS (If not, leave unchecked so we can test before merging)
• I have tested the app on Windows (If not, leave unchecked so we can test before merging)

[gauravagerwala]

Thank you for the contribution.