add instructions to test the full model

README.md

@@ -84,4 +84,7 @@ BLOCK_UID=bigscience/test-bloomd-6b3.4 pytest tests/test_block_exact_match.py
 
 # the test below will fail because there is no server that serves layer 7
 # BLOCK_UID=bigscience/test-bloomd-6b3.7 pytest tests/test_block_exact_match.py
+
+# test the full model (requires that servers collectively serve all model layers)
+REF_NAME=bigscience/bloom-6b3 pytest tests/test_full_model.py
 ```