Add release-v0.40.x to website

Signed-off-by: NVincent Demeester <vdemeest@redhat.com>

sync/config/pipelines.yaml

@@ -26,6 +26,16 @@ archive: https://github.com/tektoncd/pipeline/tags
 #       header: <dict>         # optional, no header added if not set
 #         See https://www.docsy.dev/docs/adding-content/navigation/#section-menu
 tags:
+- name: release-v0.40.x
+  displayName: v0.40.x
+  # Dict of folders to sync
+  folders:
+    docs:
+      index: README.md
+      include: ['*.md']
+      exclude:
+      - api-spec.md
+      - tutorial.md
 - name: release-v0.39.x
   displayName: v0.39.x
   # Dict of folders to sync