adding commented event_observer for mainnet

Author: wileyj

testnet/stacks-node/conf/mainnet-follower-conf.toml

@@ -13,3 +13,12 @@ peer_host = "127.0.0.1"
 # endpoint = "localhost:3700"
 # events_keys = ["*"]
 # timeout_ms = 60_000
+
+# Used if running a local stacks-signer service
+# [[events_observer]]
+# endpoint = "127.0.0.1:30000"
+# events_keys = ["stackerdb", "block_proposal", "burn_blocks"]
+
+# Used if running a local stacks-signer service
+# [connection_options]
+# auth_token = "" # fill with a unique password