feat(watch): Allow setting the starting revision

src/watch.ts

@@ -394,6 +394,14 @@ export class WatchBuilder {
     return this;
   }
 
+  /**
+   * Watch starting from a specific revision.
+   */
+  public startRevision(revision: string): this {
+    this.request.start_revision = revision;
+    return this;
+  }
+
   /**
    * watcher() creates but does not connect the watcher. Use create() instead;
    * this is mostly for testing purposes.