Images have incorrect alt attribute

[SaptakS]

Describe the bug
In the "Who we server" page, the images under the "Areas of focus" have placehold alt text and not proper alt text.

To Reproduce
Steps to reproduce the behavior:

1. Go to https://scidsg.org/who-we-serve.html#users
2. Check the alt attribute of any of the images. They are all "Unless the image is decorative, add alt text."

Expected behavior
Images should ideally have a proper alt text, i.e. "avatar representing a journalist", "avatar representing an activist". If we are not too sure about the text, we can just remove them so that the images are treated as decorative and removed from the accessibility DOM tree.