synapse workers: fix self name in workers-doc-to-yaml.awk script

roles/matrix-synapse/files/workers-doc-to-yaml.awk

@@ -5,7 +5,7 @@
 #
 # invoke in shell with:
 # URL=https://github.com/matrix-org/synapse/raw/master/docs/workers.md
-# curl -L ${URL} | awk -f parse-workers-docs.awk -
+# curl -L ${URL} | awk -f workers-doc-to-yaml.awk -
 
 function worker_stanza_append(string) {
     worker_stanza = worker_stanza string