Improved content organization for CE image guidelines

Author: Madeeks

docs/software/container-engine/examples/image-comm-fwk.md renamed to docs/software/container-engine/guidelines-images/image-comm-fwk.md

@@ -60,12 +60,12 @@ nav:
       - 'Hooks and native resources': software/container-engine/resource-hook.md
       - 'EDF reference': software/container-engine/edf.md
       - 'Guidelines for images on Alps':
-        - software/container-engine/examples/guidelines-images.md
-        - 'Communication frameworks image': software/container-engine/examples/image-comm-fwk.md
-        - 'MPICH image': software/container-engine/examples/image-mpich.md
-        - 'OpenMPI image': software/container-engine/examples/image-ompi.md
-        - 'NCCL Tests image': software/container-engine/examples/image-nccl-tests.md
-        - 'NVSHMEM image': software/container-engine/examples/image-nvshmem.md
+        - software/container-engine/guidelines-images/index.md
+        - 'Communication frameworks image': software/container-engine/guidelines-images/image-comm-fwk.md
+        - 'MPICH image': software/container-engine/guidelines-images/image-mpich.md
+        - 'OpenMPI image': software/container-engine/guidelines-images/image-ompi.md
+        - 'NCCL Tests image': software/container-engine/guidelines-images/image-nccl-tests.md
+        - 'NVSHMEM image': software/container-engine/guidelines-images/image-nvshmem.md
       - 'Known issues': software/container-engine/known-issue.md
   - 'Building and Installing Software':
     - build-install/index.md