Change Value type to just be Dynamic

Restructure into more modules.

byg/byg.cabal

@@ -21,15 +21,18 @@ library
     hs-source-dirs: src
     exposed-modules:
         Types.Token
-        Types.Values
         Types.Value
-        Types.Function
-        Types.FunctionIO
+        Types.Functions
         Types.Dependency
         Types
         DependencyGenerator
-        Function
-        FunctionIO
+        Functions.General
+        Functions.Image
+        Functions.Pandoc
+        Functions.Paths
+        Functions.Template
+        Functions.Text
+        Functions
         DependencyRunner
         SiteGenerator
         Precomputer
@@ -50,5 +53,4 @@ executable byg
     main-is: src/Main.hs
     build-depends:
         base >=4.14 && <4.20
-      , text
       , byg