chore: regenerate README

[yoshi-automation]

This PR was generated using Autosynth. 🌈

Log from Synthtool

2021-01-07 21:33:38,412 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-notification/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2021-01-07 21:33:39,286 synthtool [DEBUG] > Wrote metadata to .github/readme/synth.metadata/synth.metadata.

Full log will be available here:
https://source.cloud.google.com/results/invocations/8776903b-8d28-45d9-a396-d94622e81adc/targets

• To automatically regenerate this PR, check this box.

[codecov]

Codecov Report

Merging #223 (51f7b8d) into master (6005f69) will not change coverage.
The diff coverage is n/a.

@@            Coverage Diff            @@
##             master     #223   +/-   ##
=========================================
  Coverage     66.66%   66.66%           
  Complexity       26       26           
=========================================
  Files             2        2           
  Lines           135      135           
  Branches         18       18           
=========================================
  Hits             90       90           
  Misses           39       39           
  Partials          6        6           

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[yoshi-approver]

Rubber stamped PR!