Fix reverse-string code format (#16)

* Clarify message in case of Grapheme.split error

* Run `roc format` on reverse-string code

exercises/practice/reverse-string/.meta/Example.roc

@@ -20,7 +20,6 @@ reverse = \string ->
             Ok gs -> gs |> List.reverse |> Str.joinWith ""
             Err _ -> "Unexpected error: could not split the string into graphemes"
 
-
 ## This function reverses the input string, e.g., "hello" -> "olleh". It is
 ## faster and simpler than the implementation above, plus it does not require an
 ## external package, but it is only guaranteed to work on ASCII strings.

exercises/practice/reverse-string/ReverseString.roc

@@ -3,6 +3,6 @@ module [reverse]
 reverse = \string ->
     crash "Please implement the `reverse` function"
 
-    # HINT: we have added the `unicode` package to the app's header in
-    #       reverse-string-test.roc, so you can use it here if you need to.
-    #       For example, you could use unicode.Grapheme, just sayin'.
+# HINT: we have added the `unicode` package to the app's header in
+#       reverse-string-test.roc, so you can use it here if you need to.
+#       For example, you could use unicode.Grapheme, just sayin'.

exercises/practice/reverse-string/reverse-string-test.roc

@@ -3,7 +3,7 @@
 # File last updated on 2024-08-25
 app [main] {
     pf: platform "https://github.com/roc-lang/basic-cli/releases/download/0.14.0/dC5ceT962N_4jmoyoffVdphJ_4GlW3YMhAPyGPr-nU0.tar.br",
-    unicode: "https://github.com/roc-lang/unicode/releases/download/0.1.1/-FQDoegpSfMS-a7B0noOnZQs3-A2aq9RSOR5VVLMePg.tar.br"
+    unicode: "https://github.com/roc-lang/unicode/releases/download/0.1.1/-FQDoegpSfMS-a7B0noOnZQs3-A2aq9RSOR5VVLMePg.tar.br",
 }
 
 import pf.Task exposing [Task]
@@ -40,4 +40,3 @@ expect reverse "Würstchenstand" == "dnatsnehctsrüW"
 # grapheme clusters
 expect reverse "ผู้เขียนโปรแกรม" == "มรกแรปโนยขีเผู้"
 
-