Clarify entrypoint

entrypoint.sh

@@ -1,5 +1,12 @@
 #!/bin/sh -l
 
-echo "Hello $1"
-time=$(date)
-echo "time=$time" >> $GITHUB_OUTPUT
+# Use INPUT_<INPUT_NAME> to get the value of an input
+GREETING="Hello, $INPUT_WHO_TO_GREET!"
+
+# Use workflow commands to do things like set debug messages
+echo "::notice file=entrypoint.sh,line=7::$GREETING"
+
+# Write outputs to the $GITHUB_OUTPUT file
+echo "greeting=$GREETING" >> "$GITHUB_OUTPUT"
+
+exit 0