Added Alt-text tags in the images

[Roshanpaswan]

Add alt-text tags to foundation pages (0-3)

#62

Added alt-text tags in the images of:

1. _posts/build_fdn/2020-06-09-Atlas-Database.md
2. _posts/build_fdn/2020-06-09-Atlas-Database-config.md
3. _posts/build_fdn/2020-06-09-Data-Import.md
4. _posts/build_fdn/2020-06-09-Create-Realm.md

Checklist:

• I have read the contributor's guide.
• I linked an issue in the previous section
• I have commented on the linked issue
• I was assigned the linked issue (not required)
• I have tested the change to the best of my ability against the sandbox or a local build.
• All my images have appropriate alt tags

Optional items:

• My change adds new text and requires a change to translations.
• I was not able to test... (explain below, e.g. you did not have permissions to test a specific feature)
• This change depends O-FISH Realm repository changes (explain below)
• This change depends O-FISH Web repository changes (explain below)

• Optional: Add any explanations here

• Optional: Add any relevant screenshots here

[github-actions]

Thanks for submitting your first PR to this repository. We appreciate your contribution! Our team will review your code within 3 business days. We <3 open source and are so glad you do, too!

[Sheeri]

Hi @Roshanpaswan - your alt text is redundant. Please read the brief guide at https://wildaid.github.io/style/2020/10/02/Alt-Text.html and head over to https://webaim.org/techniques/alttext/ or https://bighack.org/how-to-write-better-alt-text-descriptions-for-accessibility/ for more examples.

[Sheeri]

Looks good!

[Sheeri]

Congratulations! 🎉 🙌 🎆 ㊗️

This PR is great and has been merged into the code. Thanks so much for contributing! If you'd like, you can request to work on another issue. We really appreciate your effort!