initialize project structure with core modules and configuration

src/state.js

@@ -0,0 +1,14 @@
+const ingestionState = new Map();
+
+function markSourceRun(source) {
+  ingestionState.set(source, new Date().toISOString());
+}
+
+function getLastIngestionBySource() {
+  return Object.fromEntries(ingestionState.entries());
+}
+
+module.exports = {
+  markSourceRun,
+  getLastIngestionBySource,
+};