doc: Different sentence

Author: camoy

README.md

@@ -3,4 +3,4 @@
 [![Build Status](https://github.com/camoy/redex-parameter/workflows/build/badge.svg)](https://github.com/camoy/redex-parameter/actions?query=workflow%3Abuild)
 [![Scribble](https://img.shields.io/badge/Docs-Scribble-blue.svg)](https://docs.racket-lang.org/redex-parameter/)
 
-Extension parameters in Redex.
+Parameters for extensions in Redex.

info.rkt

@@ -3,7 +3,7 @@
 ;; General
 
 (define collection "redex")
-(define pkg-desc "Extension parameters in Redex.")
+(define pkg-desc "Parameters for extensions in Redex.")
 (define version "0.0")
 (define pkg-authors '(camoy))
 (define scribblings '(("scribblings/redex-parameter.scrbl" ())))