chore: remove bootstrap links at index.html

[shootermv]

Summary of changes

Checklist

• I have read and followed the contribution guidelines.
• I have read through the Code of Conduct and agree to abide by the rules.
• This PR is for one of the available issues and is not a PR for an issue already assigned to someone else.
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closes #1221

[jdwilkin4]

Why are there additional style changes to the modal.css file?
It doesn't seem to be related to the issue you linked

[shootermv]

Why are there additional style changes to the modal.css file? It doesn't seem to be related to the issue you linked

actually, after removing bootstrap styles - some things become broken, thus i made several css changes...