Add missing compat bounds to docs deps (#312)

* Add missing dependency bounds

* Add missing stdlib compats

* Fix PSIS bound

docs/Project.toml

@@ -35,14 +35,18 @@ DataFrames = "1"
 DimensionalData = "0.23, 0.24"
 Distributions = "0.25"
 Documenter = "1"
+Downloads = "1.6"
 EvoTrees = "0.14.8, 0.15, 0.16"
+InferenceObjects = "0.3.11"
 MCMCDiagnosticTools = "0.3"
 MLJBase = "1"
 MLJIteration = "0.6"
 PlutoStaticHTML = "4.0.5, 5, 6"
 PlutoUI = "0.7"
 PosteriorStats = "0.1.1"
+PSIS = "0.9.1"
 StanSample = "7.0.1"
 StatisticalMeasures = "0.1"
+Statistics = "1.6"
 StatsBase = "0.32, 0.33, 0.34"
 Turing = "0.24.1, 0.25, 0.26, 0.27, 0.28"