Bump jekyll-seo-tag from 2.7.1 to 2.8.0

Bumps [jekyll-seo-tag](https://github.com/jekyll/jekyll-seo-tag) from 2.7.1 to 2.8.0.
- [Release notes](https://github.com/jekyll/jekyll-seo-tag/releases)
- [Changelog](https://github.com/jekyll/jekyll-seo-tag/blob/master/History.markdown)
- [Commits](https://github.com/jekyll/jekyll-seo-tag/compare/v2.7.1...v2.8.0)

---
updated-dependencies:
- dependency-name: jekyll-seo-tag
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Gemfile.lock

@@ -36,7 +36,7 @@ GEM
       webrick (~> 1.7)
     jekyll-sass-converter (3.0.0)
       sass-embedded (~> 1.54)
-    jekyll-seo-tag (2.7.1)
+    jekyll-seo-tag (2.8.0)
       jekyll (>= 3.8, < 5.0)
     jekyll-sitemap (1.4.0)
       jekyll (>= 3.7, < 5.0)