doc: fix minor nit introduced in readline.md

PR-URL: https://github.com/nodejs/node/pull/7198
Reviewed-By: Julian Duque <julianduquej@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

doc/api/readline.md

@@ -264,7 +264,7 @@ rl.question('What is your favorite food?', (answer) => {
 
 *Note*: The `callback` function passed to `rl.question()` does not follow the
 typical pattern of accepting an `Error` object or `null` as the first argument.
-The `callback` is called with the provided answer as the only argument.git 
+The `callback` is called with the provided answer as the only argument.
 
 ### rl.resume()
 <!-- YAML