Updated Architecture (markdown)

Architecture.md

@@ -112,9 +112,10 @@ processes the request. This issue remains to be resolved.
 ## Broker - worker communication
 
 When a worker is started, it registers itself with the broker by sending the 
-`init` command followed by headers that describe its capabilities (such as the 
-number of threads it can run simultaneously, its hardware group, languages it 
-can work with...).
+`init` command followed by its hardware group and headers that describe its 
+capabilities (such as the number of threads it can run simultaneously, 
+languages it can work with...). The headers are expected to be in following 
+format: `header_name=value`. Every header shall be in a separate frame.
 
 Whenever the broker receives an assignment suitable for the worker, it just 
 forwards the evaluation request message it originally received from the