message: docs: fix typo in observables file
  PR Close
diff: @@ -59,7 +59,7 @@ Observables are often compared to promises. Here are some key differences:
  <code-example
  path="comparing-observables/src/observables.ts"
  - header="src/observables.ts (unsubcribe)"
  + header="src/observables.ts (unsubscribe)"
  region="unsubscribe">
  </code-example>
  