Update Configurable-REPL.md

Author: coke

solutions/rakudo/Configurable-REPL.md

@@ -20,6 +20,7 @@ Each which supports the following interpolations:
 | `\i` | index - the current iteration of the REPL, which can be referred to later as, e.g. `$*1` |
 | `\l` | `$*RAKU.version` |
 | `\L` | `$*RAKU.gist` |
+| `\n` | newline |
 | `\t` | time - see below for more options |
 | `\v` | `$*RAKU.compiler.version` |
 | `\V` | `$*RAKU.gist` |