rg: Add example for searching filenames (#9856)

* rg: Add example for searching filenames

* Reduce to 8 commands

pages/common/rg.md

@@ -12,10 +12,6 @@
 
 `rg --no-ignore --hidden {{regular_expression}}`
 
-- Search for a regular expression only in a certain filetype (e.g. HTML, CSS, etc.):
-
-`rg --type {{filetype}} {{regular_expression}}`
-
 - Search for a regular expression only in a subset of directories:
 
 `rg {{regular_expression}} {{set_of_subdirs}}`
@@ -24,6 +20,10 @@
 
 `rg {{regular_expression}} --glob {{glob}}`
 
+- Search for filenames that match a regular expression:
+
+`rg --files | rg {{regular_expression}}`
+
 - Only list matched files (useful when piping to other commands):
 
 `rg --files-with-matches {{regular_expression}}`