merge and move support pages

this are now under the /support path, meaning that this is unified for
all clusters.

mkdocs.yml

@@ -122,7 +122,6 @@ nav:
       - merlin7/05-Software-Support/cray-module.env.md
     - Support:
       - merlin7/99-support/migration-from-merlin6.md
-      - merlin7/99-support/contact.md
   - Merlin 6:
     - merlin6/introduction.md
     - merlin6/hardware-and-software-description.md
@@ -183,11 +182,7 @@ nav:
       - merlin6/98-announcements/downtimes.md
       - merlin6/98-announcements/past-downtimes.md
     - Support:
-      - merlin6/99-support/contact.md
-      - merlin6/99-support/faq.md
-      - merlin6/99-support/known-problems.md
       - merlin6/99-support/migration-from-merlin5.md
-      - merlin6/99-support/troubleshooting.md
   - MeG:
     - meg/index.md
     - meg/contact.md
@@ -195,3 +190,8 @@ nav:
   - PSI@CSCS:
     - cscs-userlab/index.md
     - cscs-userlab/transfer-data.md
+  - Support:
+    - support/index.md
+    - support/faq.md
+    - support/known-problems.md
+    - support/troubleshooting.md