Bump ex_doc from 0.27.3 to 0.28.0

Bumps [ex_doc](https://github.com/elixir-lang/ex_doc) from 0.27.3 to 0.28.0.
- [Release notes](https://github.com/elixir-lang/ex_doc/releases)
- [Changelog](https://github.com/elixir-lang/ex_doc/blob/main/CHANGELOG.md)
- [Commits](elixir-lang/ex_doc@v0.27.3...v0.28.0)

---
updated-dependencies:
- dependency-name: ex_doc
  dependency-type: direct:development
  update-type: version-update:semver-minor
...

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

mix.lock

@@ -4,7 +4,7 @@
   "dialyxir": {:hex, :dialyxir, "1.1.0", "c5aab0d6e71e5522e77beff7ba9e08f8e02bad90dfbeffae60eaf0cb47e29488", [:mix], [{:erlex, ">= 0.2.6", [hex: :erlex, repo: "hexpm", optional: false]}], "hexpm", "07ea8e49c45f15264ebe6d5b93799d4dd56a44036cf42d0ad9c960bc266c0b9a"},
   "earmark_parser": {:hex, :earmark_parser, "1.4.19", "de0d033d5ff9fc396a24eadc2fcf2afa3d120841eb3f1004d138cbf9273210e8", [:mix], [], "hexpm", "527ab6630b5c75c3a3960b75844c314ec305c76d9899bb30f71cb85952a9dc45"},
   "erlex": {:hex, :erlex, "0.2.6", "c7987d15e899c7a2f34f5420d2a2ea0d659682c06ac607572df55a43753aa12e", [:mix], [], "hexpm", "2ed2e25711feb44d52b17d2780eabf998452f6efda104877a3881c2f8c0c0c75"},
-  "ex_doc": {:hex, :ex_doc, "0.27.3", "d09ed7ab590b71123959d9017f6715b54a448d76b43cf909eb0b2e5a78a977b2", [:mix], [{:earmark_parser, "~> 1.4.19", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1", [hex: :makeup_erlang, repo: "hexpm", optional: false]}], "hexpm", "ee60b329d08195039bfeb25231a208749be4f2274eae42ce38f9be0538a2f2e6"},
+  "ex_doc": {:hex, :ex_doc, "0.28.0", "7eaf526dd8c80ae8c04d52ac8801594426ae322b52a6156cd038f30bafa8226f", [:mix], [{:earmark_parser, "~> 1.4.19", [hex: :earmark_parser, repo: "hexpm", optional: false]}, {:makeup_elixir, "~> 0.14", [hex: :makeup_elixir, repo: "hexpm", optional: false]}, {:makeup_erlang, "~> 0.1", [hex: :makeup_erlang, repo: "hexpm", optional: false]}], "hexpm", "e55cdadf69a5d1f4cfd8477122ebac5e1fadd433a8c1022dafc5025e48db0131"},
   "excoveralls": {:hex, :excoveralls, "0.14.4", "295498f1ae47bdc6dce59af9a585c381e1aefc63298d48172efaaa90c3d251db", [:mix], [{:hackney, "~> 1.16", [hex: :hackney, repo: "hexpm", optional: false]}, {:jason, "~> 1.0", [hex: :jason, repo: "hexpm", optional: false]}], "hexpm", "e3ab02f2df4c1c7a519728a6f0a747e71d7d6e846020aae338173619217931c1"},
   "exometer_core": {:hex, :exometer_core, "1.6.1", "742ed00e1f10f8beff61a0f43e105c78c2f982e10f1c4e740d59df89924c65ea", [:rebar3], [{:folsom, "1.0.0", [hex: :folsom, repo: "hexpm", optional: false]}, {:hut, "1.3.0", [hex: :hut, repo: "hexpm", optional: false]}, {:parse_trans, "3.4.1", [hex: :parse_trans, repo: "hexpm", optional: false]}, {:setup, "2.1.0", [hex: :setup, repo: "hexpm", optional: false]}], "hexpm", "ec1af0a961f29b3854f61b594c79454d26ac7b1f6cb89bbf0688bff65f6a6d6b"},
   "folsom": {:hex, :folsom, "1.0.0", "50ecc998d2149939f1d5e0aa3e32788f8ed16a58e390d81b5c0be4cc4ef25589", [:rebar3], [{:bear, "1.0.0", [hex: :bear, repo: "hexpm", optional: false]}], "hexpm", "dd6ab97278e94f9e4cfc43e188224a7b8c7eaec0dd2e935007005177f3eebb0e"},