Fix link to the Hugo Theme page in Quick Start (#884)

### Prerequisites

Put an `x` into the box(es) that apply:

- [x] This pull request fixes a bug.
- [ ] This pull request adds a feature.
- [ ] This pull request introduces breaking change.

### Description

This PR fixes the link to the Hugo Theme page. 

### Issues Resolved

List any existing issues this pull request resolves.

### Checklist

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#### General

- [ ] Describe what changes are being made
- [ ] Explain why and how the changes were necessary and implemented
respectively
- [ ] Reference issue with `#<ISSUE_NO>` if applicable

#### Resources

- [ ] If you have changed any SCSS code, run `make release` to
regenerate all CSS files

#### Contributors

- [ ] Add yourself to `CONTRIBUTORS.md` if you aren't on it already

Co-authored-by: Luiz F. A. de Prá <luizdepra@users.noreply.github.com>