updated docs + added description of how internals of transforms work

Author: torfjelde

docs/make.jl

@@ -20,7 +20,7 @@ makedocs(;
         "Home" => "index.md",
         "API" => "api.md",
         "Tutorials" => ["tutorials/prob-interface.md"],
-        "Internals" => ["internals/varinfo.md"],
+        "Internals" => ["internals/varinfo.md", "internals/transformations.md"],
     ],
     checkdocs=:exports,
     doctest=false,

docs/src/api.md

@@ -270,6 +270,7 @@ resetlogp!!
 keys
 getindex
 DynamicPPL.getindex_raw
+DynamicPPL.getindex_internal
 push!!
 empty!!
 isempty
@@ -297,6 +298,8 @@ DynamicPPL.invlink
 DynamicPPL.link!!
 DynamicPPL.invlink!!
 DynamicPPL.default_transformation
+DynamicPPL.link_transform
+DynamicPPL.invlink_transform
 DynamicPPL.maybe_invlink_before_eval!!
 ```