Add support of Bootstrap 4.5.x

[lafabriqueavisuels]

Hello,
Is there a way the support of last version of Bootstrap (4.5.x) can be add ?
And to simplify the code, maybe the support of Bootstrap 3.x can be remove? (According to the wiki of Boostrap, the last update of Bootstrap 3.x dated from 2016)

Thanks

[m-ochyra]

I think there is a need to update Bootstrap. The current version has security vulnerabilities:
https://snyk.io/vuln/npm:bootstrap?lh=4.1.1

[rhukster]

Updated to latest and greatest