Fixed error in docstring

(cherry picked from commit 57a0623)

Author: GHTaarn

src/UnicodeREPL.jl

@@ -3,8 +3,8 @@
 
 On an empty line, press ^ to enter unicode_repl mode and backspace to exit.
 
-In unicode_repl mode, `\\u(XXXX)` tab completes to the symbol at Unicode
-codepage `XXXX` where `XXXX` is a hexadecimal string of any length.
+In unicode_repl mode, `\\u(XXXX)` tab completes to the symbol with Unicode
+codepoint `XXXX` where `XXXX` is a hexadecimal string of any length.
 
 ## Exported Symbols