CompatHelper: add new compat entry for DocumenterMermaid at version 0.1 for package docs, (keep existing compat) (#648)

Co-authored-by: CompatHelper Julia <compathelper_noreply@julialang.org>

Author: github-actions[bot]

docs/Project.toml

@@ -15,6 +15,7 @@ Accessors = "0.1"
 DataStructures = "0.18"
 Distributions = "0.25"
 Documenter = "1"
+DocumenterMermaid = "0.1"
 FillArrays = "0.13, 1"
 ForwardDiff = "0.10"
 LogDensityProblems = "2"