Link to function catalog docs for config props (#526)

Prior to this commit, each app documented its available config props
in its README.adoc. Now that the functions have been moved to the
function catalog, these inline docs are replaced w/ a link to the
respective function catalog docs.

See #524

applications/source/syslog-source/README.adoc

@@ -5,14 +5,8 @@ The syslog source receives SYSLOG packets over UDP, TCP, or both. RFC3164 (BSD)
 
 == Options
 
-//tag::configuration-properties[]
-$$syslog.supplier.buffer-size$$:: $$the buffer size used when decoding messages; larger messages will be rejected.$$ *($$Integer$$, default: `$$2048$$`)*
-$$syslog.supplier.nio$$:: $$Whether to use NIO (when supporting a large number of connections).$$ *($$Boolean$$, default: `$$false$$`)*
-$$syslog.supplier.port$$:: $$The port to listen on.$$ *($$Integer$$, default: `$$1514$$`)*
-$$syslog.supplier.protocol$$:: $$Protocol used for SYSLOG (tcp or udp).$$ *($$Protocol$$, default: `$$<none>$$`, possible values: `tcp`,`udp`,`both`)*
-$$syslog.supplier.reverse-lookup$$:: $$Whether to perform a reverse lookup on the incoming socket.$$ *($$Boolean$$, default: `$$false$$`)*
-$$syslog.supplier.rfc$$:: $$The '5424' or '3164' - the syslog format according to the RFC; 3164 is aka 'BSD' format.$$ *($$String$$, default: `$$3164$$`)*
-$$syslog.supplier.socket-timeout$$:: $$The socket timeout.$$ *($$Integer$$, default: `$$0$$`)*
+//tag::configuration-properties[link-to-catalog=true]
+https://github.com/spring-cloud/spring-functions-catalog/tree/main/supplier/spring-syslog-supplier#configuration-options[See Spring Functions Catalog for configuration options].
 //end::configuration-properties[]
 
 //end::ref-doc[]