Apply code review suggestions to origin doc as well

docs/data/stashcache/install-origin.md

@@ -176,11 +176,11 @@ In addition, the origin service automatically uses the following SystemD units:
 | `[email protected]` | Updates the authorization files periodically (authenticated instance) |
 
 
-Making custom additions to authorization files (optional)
----------------------------------------------------------
+Adding to Authorization Files (Optional)
+----------------------------------------
 
 The `stash-authfile` services on the origin generate files that configure authorization for XRootD.
-You can put local additions to this configuration into separate files, according to this table:
+Put local additions to this configuration into separate files, according to this table:
 
 | **Purpose**                                                    | **Generated file**                      | **Local additions file**                             |
 | :------------------------------------------------------------- | :-------------------------------------- | :--------------------------------------------------- |
@@ -189,7 +189,7 @@ You can put local additions to this configuration into separate files, according
 | SciTokens config for authenticated origin instance             | `/run/stash-origin-auth/scitokens.conf` | `/etc/xrootd/stash-origin-auth-scitokens.conf.local` |
 
 !!! note
-    These local additions files are only used in XCache 3.5.0 and newer.
+    Use of these local additions files requires XCache 3.5.0 and newer.
 
 
 Verifying the Origin Server