docs/index: Reference the actual roadmap-2022 file in the index toc

This fixes the build [1] [1] https://jenkins.softwareheritage.org/job/DDOC/job/dev/1139/console

docs/index: Reference the actual roadmap-2022 file in the index toc
929155e3 · Antoine R. Dumont · 28d0fbfe · 929155e3
Verified Commit 929155e3 authored 3 years ago by Antoine R. Dumont
--- a/docs/index.rst
+++ b/docs/index.rst
@@ -222,6 +222,7 @@ Indices and tables
   contributing/index
   tutorials/index
   faq/index
+   roadmap/roadmap-2022
   roadmap/roadmap-2021
   api-reference
   archive-changelog