Issue 21: fix typo in theme, add nav bar structure

[kaitejohnson]

Description

This PR closes #21. It fixes the typo in the _pkgdown.yaml that was preventing the enw_theme() from working and adds the formatting to the navigation bar.

For a separate issue, but we could add a preview of the site as a comment to the PR? I downloaded the artifact but either the theme still isn't working (possible) or the formatting doesn't seem to display

Tangentially related to formatting, I think I should make an issue to add back in the wordlist and spelling?

Checklist

• My PR is based on a package issue and I have explicitly linked it.
• I have included the target issue or issues in the PR title in the for Issue(s) issue-numbers: PR title
• I have read the contribution guidelines.
• I have tested my changes locally.
• I have added or updated unit tests where necessary.
• I have updated the documentation if required.
• My code follows the established coding standards.
• I have added a news item linked to this PR.
• I have reviewed CI checks for this PR and addressed them as far as I am able.

[seabbs]

Happy for this to be merged. I agree it makes sense to make a new issue to look at adding a preview - ideally that work would be done as a epinowcast action so we can use it elsewhere. We may also want a new issue to add more yaml structure and in particular a structured reference to closer match other epinowcast projects: https://github.com/epinowcast/primarycensored/blob/cb9017d39f57906350ba22522862bb2559332166/_pkgdown.yml#L10

[kaitejohnson]

Yes was thinking the same thing about the structured references -- will make a new issue to brainstorm what we would want these to be (if we want them).

Will also make an issue about the comment preview. I agree it would be a good thing to have in epinowcast, but also would want something probably very similar to the CDCgov action...