rename "Services" -> "Additional services"

context: this was discussed at a meeting at Sigma2 offices
end of September where we concluded that this will be more intuitive
since the section does not list all services and not our
"main" services but really additional services

index.md

@@ -205,7 +205,7 @@ software/eessi.md
 ```{toctree}
 :hidden:
 :maxdepth: 1
-:caption: Services
+:caption: Additional services
 
 nird_archive/user-guide.md
 nird_toolkit/overview.rst