added JET.jl as a dep to docs

Author: torfjelde

docs/Project.toml

@@ -6,6 +6,7 @@ Documenter = "e30172f5-a6a5-5a46-863b-614d45cd2de4"
 DocumenterMermaid = "a078cd44-4d9c-4618-b545-3ab9d77f9177"
 FillArrays = "1a297f60-69ca-5386-bcde-b61e274b549b"
 ForwardDiff = "f6369f11-7733-5829-9624-2563aa707210"
+JET = "c3a54625-cd67-489e-a8e7-0a5a0ff4e31b"
 LogDensityProblems = "6fdf6af0-433a-55f7-b3ed-c6c6e0b8df7c"
 MCMCChains = "c7f686f2-ff18-58e9-bc7b-31028e88f75d"
 StableRNGs = "860ef19b-820b-49d6-a774-d7a799459cd3"
@@ -18,6 +19,7 @@ Documenter = "1"
 DocumenterMermaid = "0.1"
 FillArrays = "0.13, 1"
 ForwardDiff = "0.10"
+JET = "0.9"
 LogDensityProblems = "2"
 MCMCChains = "5, 6"
 StableRNGs = "1"