Feat: Add full CRUD support for quotes APIs and documentation updates for quotes resource

[nayan-kunwar]

Currently the quotes resource supports read operations.

I would like to enhance it by adding full CRUD support:

• POST /quotes/add
• PUT /quotes/:id
• PATCH /quotes/:id
• DELETE /quotes/:id

These endpoints simulate write operations (consistent with other resources in the project).

Additionally, I have updated the documentation page:

• Added sections for Add, Update(PUT or PATCH), and Delete operations
• Updated side navigation links
• Included example fetch requests and JSON responses
• Maintained consistency with existing documentation format (EJS structure)

This improves API consistency across resources and keeps the documentation aligned with the available endpoints.

Please let me know if you're open to this contribution.