chore: regenerate README (#721)

This PR was generated using Autosynth. 🌈


<details><summary>Log from Synthtool</summary>

```
2021-05-26 21:42:30,001 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-asset/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2021-05-26 21:42:31,678 synthtool [DEBUG] > Wrote metadata to .github/readme/synth.metadata/synth.metadata.

```
</details>

Full log will be available here:
https://source.cloud.google.com/results/invocations/a184a0d3-bb46-4ac7-9a05-3c2fc9847ff6/targets

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.github/readme/synth.metadata/synth.metadata

@@ -4,7 +4,7 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-asset.git",
-        "sha": "646d67386bd6f11e532ba96ae4c4b309e4037eb1"
+        "sha": "492a4fe7fc80d03f8ec884817574d81021921e2b"
       }
     },
     {

README.md

@@ -39,7 +39,7 @@ If you are using Maven without BOM, add this to your dependencies:
 <dependency>
   <groupId>com.google.cloud</groupId>
   <artifactId>google-cloud-asset</artifactId>
-  <version>2.3.5</version>
+  <version>2.3.6</version>
 </dependency>
 
 ```