docs: Added "WageSlav3" to showcase (#2405)

Co-authored-by: Patryk Kuniczak <p.kuniczak@gmail.com>

Author: slovakian

docs/assets/extension-showcase.yml

@@ -477,3 +477,6 @@
 - # Property Track - https://www.propertytrack.co
   chromeId: ahknifalnhmbanoclebllcolcdomfdop
   firefoxSlug: propertytrack
+
+- # WageSlav3
+  chromeId: anhkcmapjhiiofpcgglfljphdgppilof