add explanation to large disk entry

Author: d4straub

.github/workflows/nf-test.yml

@@ -64,7 +64,7 @@ jobs:
     runs-on: # use self-hosted runners
       - runs-on=${{ github.run_id }}-nf-test
       - runner=4cpu-linux-x64
-      - disk=large
+      - disk=large # '-profile test_multiregion' with singularity requires the larger disk
     strategy:
       fail-fast: false
       matrix: