chore: regenerate README

[yoshi-automation]

This PR was generated using Autosynth. 🌈

Log from Synthtool

2021-03-17 18:33:03,814 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-bigquerystorage/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2021-03-17 18:33:04,808 synthtool [DEBUG] > Wrote metadata to .github/readme/synth.metadata/synth.metadata.

Full log will be available here:
https://source.cloud.google.com/results/invocations/d68f9bb3-64b6-4fe5-b8e5-abfbef058c57/targets

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[yoshi-approver]

Rubber stamped PR!

[codecov]

Codecov Report

Merging #944 (c6e56e1) into master (1554247) will increase coverage by 0.03%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##             master     #944      +/-   ##
============================================
+ Coverage     80.95%   80.99%   +0.03%     
  Complexity     1021     1021              
============================================
  Files            76       76              
  Lines          5556     5556              
  Branches        427      427              
============================================
+ Hits           4498     4500       +2     
+ Misses          881      879       -2     
  Partials        177      177              

Impacted Files	Coverage Δ	Complexity Δ
...e/cloud/bigquery/storage/v1beta2/StreamWriter.java	83.25% <0.00%> (+0.45%)	33.00% <0.00%> (ø%)

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