Move the schema.org/BreadcrumbList stuff out of Foundation

src/SchemaOrg/BreadcrumbList.hs

@@ -0,0 +1,21 @@
+{-# LANGUAGE OverloadedStrings #-}
+module SchemaOrg.BreadcrumbList ( breadcrumbList ) where
+
+import Data.Aeson
+import qualified Data.Text as T
+
+breadcrumbList :: [(a, T.Text)] -> (a -> [(T.Text, T.Text)] -> T.Text) -> Value
+breadcrumbList crumbs url = object
+  [ ("@context", "http://schema.org")
+  , ("@type", "BreadcrumbList")
+  , "itemListElement" .= zipWith (listItem url) [1 :: Int ..] crumbs
+  ]
+listItem :: (a -> [(T.Text, T.Text)] -> T.Text) -> Int -> (a, T.Text) -> Value
+listItem url i (r, t) = object
+  [ ("@type", "ListItem")
+  , "position" .= i
+  , "item" .= object
+    [ "@id" .= url r []
+    , "name" .= t
+    ]
+  ]