loadtest: add asset type field on sample conf

Our loadtest config supports defining the asset type to use across the
loadtests. In this commit we just add it to the sample file to raise
awareness of this field for the user.

Author: GeorgeTsagk

itest/loadtest/loadtest-sample.conf

@@ -22,6 +22,10 @@ send-test-num-sends=5
 # Number of assets to send in each send operation for send test
 send-test-num-assets=1
 
+# Type of asset to use in the test case. For V2 test cases, a 0 type is
+# required.
+send-test-send-type=0
+
 # Timeout for the entire test suite
 test-suite-timeout=120m