chore: regens API reference docs (#889)

diff --git a/docs/dyn/pubsub_v1.projects.topics.snapshots.html b/docs/dyn/pubsub_v1.projects.topics.snapshots.html
index 6a775c2..694a985 100644
--- a/docs/dyn/pubsub_v1.projects.topics.snapshots.html
+++ b/docs/dyn/pubsub_v1.projects.topics.snapshots.html
@@ -84,14 +84,14 @@
 <div class="method">
     <code class="details" id="list">list(topic, pageSize=None, pageToken=None, x__xgafv=None)</code>
   <pre>Lists the names of the snapshots on this topic. Snapshots are used in
-<a href="https://cloud.google.com/pubsub/docs/replay-overview">Seek</a>
+&lt;a href="https://cloud.google.com/pubsub/docs/replay-overview"&gt;Seek&lt;/a&gt;
 operations, which allow
 you to manage message acknowledgments in bulk. That is, you can set the
 acknowledgment state of messages in an existing subscription to the state
 captured by a snapshot.
 
 Args:
-  topic: string, The name of the topic that snapshots are attached to.
+  topic: string, Required. The name of the topic that snapshots are attached to.
 Format is `projects/{project}/topics/{topic}`. (required)
   pageSize: integer, Maximum number of snapshot names to return.
   pageToken: string, The value returned by the last `ListTopicSnapshotsResponse`; indicates