Update Documenter requirement to 1.16.1 in /docs

Updates the requirements on [Documenter](https://github.com/JuliaDocs/Documenter.jl) to permit the latest version.
- [Release notes](https://github.com/JuliaDocs/Documenter.jl/releases)
- [Changelog](https://github.com/JuliaDocs/Documenter.jl/blob/master/CHANGELOG.md)
- [Commits](JuliaDocs/Documenter.jl@v0.1.0...v1.16.1)

---
updated-dependencies:
- dependency-name: Documenter
  dependency-version: 1.16.1
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

docs/Project.toml

@@ -11,3 +11,6 @@ Plots = "91a5bcdd-55d7-5caf-9e0b-520d859cae80"
 RData = "df47a6cb-8c03-5eed-afd8-b6050d6c41da"
 StatsPlots = "f3b207a7-027a-5e70-b257-86293d7955fd"
 Suppressor = "fd094767-a336-5f1f-9728-57cf17d0bbfb"
+
+[compat]
+Documenter = "1.16.1"