Update readme and add some deps

README.md

@@ -20,7 +20,7 @@ ottyl reads the logs via stdin and indexes it in-memory in a BTreeMap for proper
 This is the main program, hosting the webapp over axum.
 
 The engine reads stdin and sends line-split messages to a log ingester.
-The log ingester holds a mutex over a BTreeMap<IndexKey, DataValue>.
+The log ingester holds a BTreeMap<IndexKey, DataValue>.
 
 The BTreeMap may be a custom variation of the std library one, because we need to be able to scan specific ranges and jump to keys.
 ```
@@ -90,6 +90,19 @@ enum MetricPrimitive {
 }
 ```
 
+## Tasks
+
+The ingestion tasks reads stdin, sequences the logs, timestamps them and sends over a channel to the engine task.
+
+The engine task processes incoming logs and incoming requests.
+It should be lock-free and the sole-owner of the btreemap.
+
+Axum is not a specific task, but exists and serves the API and frontend.
+API requests get validated (like, correct syntax etc etc) and then requests are sent over a channel to the engine.
+The request includes a byte buffer, for response serialisation to go into it.
+The engine does the serialisation, because it is the sole owner of the btreemap and should not be copying memory simply to serialise it later.
+A callback is given, so the API knows the request is processed and response is ready to send back from the byte buffer.
+Rkyv can be used if that helps, otherwise sending raw bytes is fine as well.
 
 # WebApp
 
@@ -174,4 +187,22 @@ There should be support for promql queries to derive the visualisation.
 Supported charts should be bar chart, line chart, and pie chart.
 
 
+# Ideas
+
+This part describes ideas that can be implemented in the future, but not now.
+
+## Ntfy.sh alerts
+
+Have matchers you are interested in.
+Configure the ntfy.sh channel.
+Send to the channel when an event triggers.
+
+## Sequence diagram of events
+
+It would be awesome if it were possible to declare participants of a sequence diagram using parameters or matchers.
+Example `node_id` for a cluster test or something.
+Then it may be possible to capture specific events of interest.
+There wouldn't be a relation between nodes, only the sequence of events determines relations in the sequence diagram.
+
+