chore: regenerate README

[yoshi-automation]

This PR was generated using Autosynth. 🌈

Log from Synthtool

2021-02-24 19:41:56,202 synthtool [DEBUG] > Executing /root/.cache/synthtool/java-dns/.github/readme/synth.py.
On branch autosynth-readme
nothing to commit, working tree clean
2021-02-24 19:41:57,703 synthtool [DEBUG] > Wrote metadata to .github/readme/synth.metadata/synth.metadata.

Full log will be available here:
https://source.cloud.google.com/results/invocations/630c08c4-0b83-40f7-b4fe-b46c86c4f5db/targets

• To automatically regenerate this PR, check this box.

[codecov]

Codecov Report

Merging #325 (7464cfa) into master (6483700) will decrease coverage by 0.09%.
The diff coverage is n/a.

@@             Coverage Diff              @@
##             master     #325      +/-   ##
============================================
- Coverage     77.26%   77.16%   -0.10%     
  Complexity      178      178              
============================================
  Files            15       15              
  Lines          1192     1187       -5     
  Branches        105      100       -5     
============================================
- Hits            921      916       -5     
+ Misses          218      217       -1     
- Partials         53       54       +1     

Impacted Files	Coverage Δ	Complexity Δ
src/main/java/com/google/cloud/dns/DnsBatch.java	90.55% <0.00%> (-0.36%)	20.00% <0.00%> (ø%)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 6483700...7464cfa. Read the comment docs.

[yoshi-approver]

Rubber stamped PR!