docs: Add good first issue section (#59)

* Add 'Good First Issues' section to README

Added a section for 'Good First Issues' to guide new contributors.

Signed-off-by: freya-docs <freya.docs.pp@gmail.com>

* Fix grammar in Good First Issues section

Corrected punctuation and improved sentence structure for clarity.

Signed-off-by: freya-docs <freya.docs.pp@gmail.com>

---------

Signed-off-by: freya-docs <freya.docs.pp@gmail.com>
Signed-off-by: xingzihai

Author: freya-docs

README.md

@@ -251,6 +251,21 @@ The following error cases are implemented:
 | **Set Default Card** | 404 | `{ error: 'Card not found' }` — when card ID doesn't exist or doesn't belong to authenticated user |
 | **Successful Deletion** | 204 | No content |
 
+## Good First Issues
+
+New to open source? We've got you covered! Check out our [Good First Issues](https://github.com/Dev-Card/DevCard/issues?q=is%3Aopen+label%3A%22good-first-issue%22), these are specially curated issues that are:
+
+- Well-documented with clear acceptance criteria
+- Limited in scope (perfect for a first contribution)
+- Mentored by maintainers
+
+### How to Claim an Issue
+
+1. Browse the [Good First Issues list](https://github.com/Dev-Card/DevCard/issues?q=is%3Aopen+label%3A%22good-first-issue%22).
+2. Comment on the issue you'd like to work on (e.g., "I'd like to take this on!") and wait for a maintainer to assign it to you.
+3. If you feel like opening the PR first, you can do that, and you will be assigned accordingly.
+4. Fork the repo, make your changes, and open a PR.
+
 ## Contributing
 
 See [CONTRIBUTING.md](./CONTRIBUTING.md) for setup instructions, coding standards, and PR process.