Fix typo in siege command

 Fixes #75
 s/seige/siege

Author: navidshaikh

documentation/modules/ROOT/pages/03scaling.adoc

@@ -343,7 +343,7 @@ We will now send some load to the greeter service.  The command below sends 50 c
 
 [source,bash,subs="+macros,+attributes",linenums]
 ----
-seige -r 1 -c 50 -t 30S -d 2 \
+siege -r 1 -c 50 -t 30S -d 2 \
   -H "Host: greeter.knativetutorial.example.com" \
   "http://pass:[${IP_ADDRESS}]"
 ----