docs(no-ignored-observable): tips for this rule

Author: JasonWeinzierl

docs/rules/no-ignored-observable.md

@@ -7,6 +7,17 @@
 <!-- end auto-generated rule header -->
 
 The effects failures if an observable returned by a function is neither assigned to a variable or property or passed to a function.
+This rule is like [no-floating-promises](https://typescript-eslint.io/rules/no-floating-promises/) but for Observables.
+
+This rule will report Observable-valued statements that are not treated in one of the following ways:
+
+- Calling its `.subscribe()`
+- `return`ing it
+- Wrapping it in `lastValueFrom` or `firstValueFrom` and `await`ing it
+- [`void`ing it](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/void)
+
+> [!TIP]
+> `no-ignored-observable` only detects apparently unhandled Observable _statements_.
 
 ## Rule details
 

tests/rules/no-ignored-observable.test.ts

@@ -31,6 +31,16 @@ ruleTester({ types: true }).run('no-ignored-observable', noIgnoredObservableRule
       const a = arrowSource();
       sink(arrowSource());
     `,
+    stripIndent`
+      // void operator
+      import { of } from "rxjs";
+
+      function functionSource() {
+        return of(42);
+      }
+
+      void functionSource();
+    `,
   ],
   invalid: [
     fromFixture(