Added search_up() as documented alias of findfiles_up()

search_up() is an undocumented alias for findfiles_up() that has
existed since 3.18. Added a Hugo alias so /reference/functions/search_up
redirects to the findfiles_up page, and noted the alias in the
description.

Author: nickanderson

content/reference/functions/findfiles_up.markdown

@@ -3,12 +3,13 @@ layout: default
 title: findfiles_up
 aliases:
   - "/reference-functions-findfiles_up.html"
+  - "/reference/functions/search_up"
 ---
 
 {{< CFEngine_function_prototype(path, glob, level) >}}
 
 **Description:** Return a data array of files that match a given glob pattern
-by searching up the directory tree.
+by searching up the directory tree. Also available as `search_up()`.
 
 This function searches for files matching a given glob pattern `glob` in the
 local filesystem by searching up the directory tree from a given absolute

generator/_references.md

@@ -64,3 +64,4 @@
 [mpf-services-autorun]: reference-masterfiles-policy-framework-services-autorun.html
 [package-modules-the-api]: reference-language-concepts-modules-package-module-api.html#the-api
 [Functions#collecting functions]: /reference/functions/#collecting-functions
+[search_up]: /reference/functions/findfiles_up "search_up"