Remove refs/reqs to unused modules

Move one to build-only dep

Most of #3480

CONTRIBUTING.md

@@ -251,20 +251,10 @@ downloading the latest Rakudo Star release from
 installed Rakudo Star package, it should already be there. Feel free to
 use any other module installer for the modules needed (see below).
 
-#### Building the documentation
-
-The program that builds the HTML version of the documentation
-(`htmlify.p6`) uses `Pod::To::HTML` to convert Pod6 structures into HTML.
-You'll also need `Pod::To::BigPage` and `Perl6::TypeGraph`. Install these modules like so:
-
-    $ zef install Pod::To::HTML Pod::To::BigPage Perl6::TypeGraph
-
-although these are included in the `META.json` file so with
+To install any prerequistes for this module, use:
 
     $ zef install --deps-only .
 
-you're good to go.
-
 #### Mojolicious / Web Server
 
 This is a Perl web framework which is used to run the included

META6.json

@@ -8,14 +8,9 @@
   ],
   "auth": "perl6",
   "depends": [
-    "URI",
     "File::Temp",
-    "JSON::Fast",
     "Pod::To::BigPage:ver<0.5.1+>",
     "Pod::To::HTML:ver<0.6.1+>",
-    "Pod::Utilities",
-    "OO::Monitors",
-    "File::Find",
     "Test::META",
     "Perl6::TypeGraph"
   ],