[GN docs] Add missing word in gn actions help string

gn actions help said "run a script a single time to produce or more
output files". Add the missing "one" to make this "one or more output
files".

BUG=None

Review-Url: https://codereview.chromium.org/2133873002
Cr-Original-Commit-Position: refs/heads/master@{#404533}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: bf462ea0de8604630aecc49e976c3bd9d646a4a0
diff --git a/tools/gn/docs/reference.md b/tools/gn/docs/reference.md
index e1ae36e..ff096cc 100644
--- a/tools/gn/docs/reference.md
+++ b/tools/gn/docs/reference.md
@@ -1048,8 +1048,8 @@
 
 ```
   This target type allows you to run a script a single time to produce
-  or more output files. If you want to run a script once for each of a
-  set of input files, see "gn help action_foreach".
+  one or more output files. If you want to run a script once for each of
+  a set of input files, see "gn help action_foreach".
 
 ```
 
diff --git a/tools/gn/functions_target.cc b/tools/gn/functions_target.cc
index 5cfd20b..4e162d5 100644
--- a/tools/gn/functions_target.cc
+++ b/tools/gn/functions_target.cc
@@ -91,8 +91,8 @@
     "action: Declare a target that runs a script a single time.\n"
     "\n"
     "  This target type allows you to run a script a single time to produce\n"
-    "  or more output files. If you want to run a script once for each of a\n"
-    "  set of input files, see \"gn help action_foreach\".\n"
+    "  one or more output files. If you want to run a script once for each of\n"
+    "  a set of input files, see \"gn help action_foreach\".\n"
     "\n"
     "Inputs\n"
     "\n"