RB: add missing QLDoc

ruby/ql/lib/codeql/ruby/security/StoredXSSQuery.qll

@@ -11,6 +11,7 @@ import ruby
 import codeql.ruby.DataFlow
 import codeql.ruby.TaintTracking
 
+/** Provides a taint-tracking configuration for cross-site scripting vulnerabilities. */
 module StoredXss {
   import XSS::StoredXss
 

ruby/ql/lib/codeql/ruby/security/XSS.qll

@@ -318,6 +318,7 @@ private module OrmTracking {
   }
 }
 
+/** Provides default sources, sinks and sanitizers for detecting stored cross-site scripting (XSS) vulnerabilities. */
 module StoredXss {
   /** A data flow source for stored XSS vulnerabilities. */
   abstract class Source extends Shared::Source { }