improved guildelines for contributing

[wre9-tesh]

Description

Added guidelines to prevent missing images and broken links.
Fixes: #640

Type of change

• [x] This change requires a documentation update

Checklist:

• [x] I have made corresponding changes to the documentation
• [x] My changes generate no new warnings

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[github-actions[bot]]

Our team will soon review your PR. Thanks @wre9-tesh :)

[github-actions[bot]]

Thank you @wre9-tesh for taking out your valuable time in order to contribute to our project. Looking forward for more such amazing contributions :)