Make it easier to discover the format fp trick. Fixes #97

src/Turtle/Prelude.hs

@@ -52,6 +52,12 @@
 -- 456
 -- ABC
 --
+-- Format strings in a type safe way using `format`:
+--
+-- >>> dir <- pwd
+-- >>> format ("I am in the "%fp%" directory") dir
+-- "I am in the /tmp directory"
+--
 -- Commands like `grep`, `sed` and `find` accept arbitrary `Pattern`s
 --
 -- >>> stdout (grep ("123" <|> "ABC") (input "foo.txt"))

src/Turtle/Tutorial.hs

@@ -777,6 +777,10 @@ import Turtle
 -- another argument of type `Int` to satisfy the `d` at the end of the format
 -- string.
 --
+-- Note that this is also the idiomatic way to convert a `FilePath` to `Text`:
+--
+-- > format fp :: FilePath -> Text
+--
 -- If you are interested in this feature, check out the "Turtle.Format" module
 -- for more details.