runtime(doc): minor spell fix in starting.txt

closes: #14608

Signed-off-by: Diego Viola <diego.viola@gmail.com>
diff --git a/runtime/doc/starting.txt b/runtime/doc/starting.txt
index 455a04a..b83a61e 100644
--- a/runtime/doc/starting.txt
+++ b/runtime/doc/starting.txt
@@ -1,4 +1,4 @@
-*starting.txt*  For Vim version 9.1.  Last change: 2024 Apr 20
+*starting.txt*  For Vim version 9.1.  Last change: 2024 Apr 21
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -1097,7 +1097,7 @@
 https://specifications.freedesktop.org/basedir-spec/latest/
 
 The location of this standard configuration directory is configurable by the
-user, using environment variable but should also give fallback in case those
+user, using an environment variable but should also give fallback in case those
 variables weren't set.
 
 This is not an exhaustive list of those directories: