feat: develop links & resources page

[sakshi-choudhary]

ISSUE #310

Describe the changes you've made

Developed a Links & Resources page.

Describe if there is any unusual behavior (Any Warning) of your code(Write NA if there isn't) NA

Additional context (OPTIONAL) I have rendered conditionally so if the link / doc does not have a preview image, it will be rendered without an image.

Checklist

• [x] My code follows the code style of this project.
• [ ] My change requires a change to the documentation.
• [ ] I have updated the documentation accordingly.
• [ ] All new and existing tests passed.
• [x] The title of my pull request is a short description of the requested changes.

Provide a Deployed link of route/page that needs to review Preview: https://deploy-preview-311--edu-client.netlify.app/resources/:coursename