reword description of the builders-use-substitutes setting

src/libstore/globals.hh

@@ -276,13 +276,10 @@ public:
     Setting<bool> buildersUseSubstitutes{
         this, false, "builders-use-substitutes",
         R"(
-          If set to `true`, Nix will instruct remote build machines to use
-          their own binary substitutes if available. In practical terms, this
-          means that remote hosts will fetch as many build dependencies as
-          possible from their own substitutes (e.g, from `cache.nixos.org`),
-          instead of waiting for this host to upload them all. This can
-          drastically reduce build times if the network connection between
-          this computer and the remote build host is slow.
+          If set to `true`, Nix will instruct [remote build machines](#conf-builders) to use their own [`substituters`](#conf-substituters) if available.
+
+          In practical terms, this means that remote build hosts will fetch as many dependencies as possible from their own substitutes (e.g, from `cache.nixos.org`) instead of waiting for the local machine to upload them all.
+          This can drastically reduce build times if the network connection between the local machine and the remote build host is slow.
         )"};
 
     Setting<off_t> reservedSize{this, 8 * 1024 * 1024, "gc-reserved-space",