doc: fix typo in repl.md

PR-URL: #17502
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: Jon Moss <me@jonathanmoss.me>
Reviewed-By: Minwoo Jung <minwoo@nodesource.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>

Author: Trott

doc/api/repl.md

@@ -418,7 +418,7 @@ changes:
   * `output` {Writable} The Writable stream to which REPL output will be
     written. Defaults to `process.stdout`.
   * `terminal` {boolean} If `true`, specifies that the `output` should be
-    treated as a a TTY terminal, and have ANSI/VT100 escape codes written to it.
+    treated as a TTY terminal, and have ANSI/VT100 escape codes written to it.
     Defaults to checking the value of the `isTTY` property on the `output`
     stream upon instantiation.
   * `eval` {Function} The function to be used when evaluating each given line