[feat] engines: add repology.org engine for linux packages (#5103)

Repology_ monitors a huge number of package repositories and other sources
comparing packages versions across them and gathering other information.

Repology_ shows you in which repositories a given project is packaged, which
version is the latest and which needs updating, who maintains the package, and
other related information.

.. _Repology: https://repology.org/docs/about

Co-authored-by: Markus Heiser <markus.heiser@darmarit.de>
Format: reST

searx/settings.yml

@@ -2525,6 +2525,12 @@ engines:
     categories: videos
     disabled: true
 
+  - name: repology
+    engine: repology
+    shortcut: rep
+    disabled: true
+    inactive: true
+
   - name: livespace
     engine: livespace
     shortcut: ls