fix for Bootstrap v5

[mat-dr]

No description provided.

[rgelb]

This fixes it partially. The calling HTML page needs to have a reference to the popper.js library as its now required for bootstrap 5 dropdowns.

[mat-dr]

Yes it requires Popper. It is also possible to only include the Bootstrap .js file that includes Popper (bootstrap.bundle.min.js, as in https://getbootstrap.com/docs/5.2/getting-started/introduction/).

[Taikono-Himazin]

I'm sorry, but could you merge it and release it as bootstrap-multiselect-v2.0.0?
That's all there is to it.

[tiesont]

That's all there is to it.

Not really.

Feel free to fork the repo and merge any changes you're comfortable using, if you really want this or other pull-requests.

[utilmind]

@mat-dr Thank you for this PR! It works great on BS5 with your fix.

[codingdna2]

I'm sorry, but could you merge it and release it as bootstrap-multiselect-v2.0.0? That's all there is to it.

I also found that there are other minor issues like with buttonTextAlignment option.
In BS5 text-left should be text-start and text-right should be text-end