chore: regenerate README (#207)

This PR was generated using Autosynth. 🌈


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

```
2021-03-03 19:44:55,483 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-workflows/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2021-03-03 19:44:56,635 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/a791fcdd-bd1a-4c60-90d3-3e14d8642dca/targets

- [ ] To automatically regenerate this PR, check this box.

java-workflows/.github/readme/synth.metadata/synth.metadata

@@ -4,14 +4,14 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-workflows.git",
-        "sha": "607f9904330c68f624c37d040e2ffc5ab735ef50"
+        "sha": "2d7d5e1f8adb0e9c687893119842b1a3def75771"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "21da7d9fa02f6916d9f87cf4072b3547b5c72eb5"
+        "sha": "2e7bd5cc66a3f0b90ce1c150eb35c89eeb9872d6"
       }
     }
   ]

java-workflows/README.md

@@ -20,7 +20,7 @@ If you are using Maven, add this to your pom.xml file:
 <dependency>
   <groupId>com.google.cloud</groupId>
   <artifactId>google-cloud-workflows</artifactId>
-  <version>0.2.0</version>
+  <version>0.2.1</version>
 </dependency>
 
 ```