drush: switch to Drupal 8 examples (#3559)

pages/common/drush.md

@@ -3,25 +3,17 @@
 > A command-line shell and scripting interface for Drupal.
 > More information: <https://www.drush.org>.
 
-- Download module "foo":
-
-`drush dl {{foo}}`
-
-- Download version 7.x-2.1-beta1 of module "foo":
-
-`drush dl {{foo}}-7.x-2.1-beta1`
-
 - Enable module "foo":
 
 `drush en {{foo}}`
 
-- Disable module "foo":
+- Uninstall module "foo":
 
-`drush dis {{foo}}`
+`drush pmu {{foo}}`
 
 - Clear all caches:
 
-`drush cc all`
+`drush cr`
 
 - Clear CSS and JavaScript caches: