docs: update README about section

.readme-partials.yaml

@@ -97,3 +97,23 @@ custom_content: |
     ```java
     spark.readStream.format("pubsublite").option("gcp.credentials.key", "<SERVICE_ACCOUNT_JSON_IN_BASE64>")
     ```
+about: |
+  [Google Cloud Pub/Sub Lite][product-docs] is designed to provide reliable,
+  many-to-many, asynchronous messaging between applications. Publisher
+  applications can send messages to a topic and other applications can
+  subscribe to that topic to receive the messages. By decoupling senders and
+  receivers, Google Cloud Pub/Sub allows developers to communicate between
+  independently written applications.
+
+  Compared to Google Pub/Sub, Pub/Sub Lite provides partitioned zonal data
+  storage with predefined capacity. Both products present a similar API, but
+  Pub/Sub Lite has more usage caveats.
+
+  See the [Pub/Sub Lite docs](https://cloud.google.com/pubsub/quickstart-console#before-you-begin) for more details on how to activate
+  Pub/Sub Lite for your project, as well as guidance on how to choose between
+  Cloud Pub/Sub and Pub/Sub Lite.
+
+  See the [Pub/Sub Lite client library docs][javadocs] to learn how to
+  use this Pub/Sub Lite Client Library.
+
+  The Pub/Sub Lite Spark connector ...