Capitalize PATH in README

README.md

@@ -55,9 +55,9 @@ multiple cores available.
 
 ### Custom `makeinfo` path
 
-By default, Quickref will use the `makeinfo` found in your path to generate the
-`.texi` files, but you can provide a custom one by calling Quickref with the
-`:makeinfo-path` keyword argument:
+By default, Quickref will use the `makeinfo` found in your `PATH` to generate
+the `.texi` files, but you can provide a custom one by calling Quickref with
+the `:makeinfo-path` keyword argument:
 
 ```lisp
 (quickref:refresh :makeinfo-path "/usr/local/bin/makeinfo")