chore: regenerate README (#614)
chore: regenerate README (#614)

This PR was generated using Autosynth. :rainbow:


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

```
2021-07-29 08:50:46,280 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-language/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2021-07-29 08:50:47,471 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/ed3a558b-45f9-49c1-8387-0fd8528539ac/targets

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