chore: cleanup and document activity_name optional field properly

Author: Ifeanyichukwu

README.md

@@ -153,6 +153,7 @@ but destination nodes can be any public node in the network (though
 this may result in liquidity draining over time).
 
 Required fields:
+
 ```
 "source": the payer
 "destination": the payee
@@ -161,22 +162,27 @@ Required fields:
 ```
 
 Optional fields:
+
 ```
 "start_secs": the time to start sending payments
 "count": the total number of payments to send
+"activity_name": an optional name for each activity description, used as the logging prefix to relate logs to their corresponding activity
 ```
 
 > If `start_secs` is not provided the payments will begin as soon as the simulation starts (default=0)
 
 > If `count` is not provided the payments will continue for as long as the simulation runs (default=None)
 
+> If `activity_name` is not provided the index of each activity description will be used as the logging prefix
+
 The example simulation file below sets up the following simulation:
-* Connect to `Alice` running LND to generate activity.
-* Connect to `Bob` running CLN to generate activity.
-* Dispatch 2000 msat payments from `Alice` to `Carol` every 1 seconds.
-* Dispatch 140000 msat payments from `Bob` to `Alice` every 50 seconds.
-* Dispatch 1000 msat payments from `Bob` to `Dave` every 2 seconds.
-* Dispatch 10 payments (5000 msat each) from `Erin` to `Frank` at 2 second intervals, starting 20 seconds into the sim.
+
+- Connect to `Alice` running LND to generate activity.
+- Connect to `Bob` running CLN to generate activity.
+- Dispatch 2000 msat payments from `Alice` to `Carol` every 1 seconds.
+- Dispatch 140000 msat payments from `Bob` to `Alice` every 50 seconds.
+- Dispatch 1000 msat payments from `Bob` to `Dave` every 2 seconds.
+- Dispatch 10 payments (5000 msat each) from `Erin` to `Frank` at 2 second intervals, starting 20 seconds into the sim.
 
 ```
 {
@@ -198,13 +204,13 @@ The example simulation file below sets up the following simulation:
       "id": "Erin",
       "address": "https://localhost:10012",
       "macaroon": "/path/admin.macaroon",
-      "cert": "/path/tls.cert"      
+      "cert": "/path/tls.cert"
     },
     {
       "id": "Frank",
       "address": "https://localhost:10014",
       "macaroon": "/path/admin.macaroon",
-      "cert": "/path/tls.cert"      
+      "cert": "/path/tls.cert"
     }
   ],
   "activity": [