Update bootstrap-themes-in-teal.Rmd

[abodoni]

Fixed one line by adding needed bracket

[github-actions]

CLA Assistant Lite bot:
🎉 Thank you for your contribution! Before this PR can be accepted, we require that you read and agree to our Contributor License Agreement.
You can digitally sign the CLA by posting a comment on this Pull Request in the format shown below. This agreement will apply to this PR as well as all future contributions on this repository.

---

I have read the CLA Document and I hereby sign the CLA

---

_{You can retrigger this bot by commenting recheck in this Pull Request}

[Polkas]

@gogonzo please be aware of this one liner:)

[gogonzo]

Thanks for this!