semantic-scholar-client: Extend Readme

semantic-scholar-client/README.md

@@ -2,3 +2,15 @@ This utility is able to fetch data fromSemantic Scholar API.
 
 Initial proof of concept here writes the result to stdout. Work in progress to pipe this data into an operating database.
 
+### Usage
+
+    cargo run -- --paper-id <paper_id>
+
+`paper_id` is in accordance with [Semantic Scholar API](https://api.semanticscholar.org/api-docs/) rules.
+
+In its current form the utility outputs the citation graph up to a depth of 3 citations.
+
+Next steps include
+- developing strategies for deciding where to terminate a given traversal
+- providing an HTTP and perhaps WebSocket interface that can be used to talk to this process during its operation.
+  This can enable us to pipe the data to other tasks, to monitor, to start/stop, and even to make configuration changes.