Update README

Author: tianon

README.md

@@ -19,6 +19,6 @@ For outstanding `logstash` image PRs, check [PRs with the "library/logstash" lab
 
 | Build | Status | Badges | (per-arch) |
 |:-:|:-:|:-:|:-:|
-| [![amd64 build status badge](https://img.shields.io/jenkins/s/https/doi-janky.infosiftr.net/job/multiarch/job/amd64/job/logstash.svg?label=amd64)](https://doi-janky.infosiftr.net/job/multiarch/job/amd64/job/logstash/) | [![put-shared build status badge](https://img.shields.io/jenkins/s/https/doi-janky.infosiftr.net/job/put-shared/job/light/job/logstash.svg?label=put-shared)](https://doi-janky.infosiftr.net/job/put-shared/job/light/job/logstash/) |
+| [![amd64 build status badge](https://img.shields.io/jenkins/s/https/doi-janky.infosiftr.net/job/multiarch/job/amd64/job/logstash.svg?label=amd64)](https://doi-janky.infosiftr.net/job/multiarch/job/amd64/job/logstash/) | [![arm64v8 build status badge](https://img.shields.io/jenkins/s/https/doi-janky.infosiftr.net/job/multiarch/job/arm64v8/job/logstash.svg?label=arm64v8)](https://doi-janky.infosiftr.net/job/multiarch/job/arm64v8/job/logstash/) | [![put-shared build status badge](https://img.shields.io/jenkins/s/https/doi-janky.infosiftr.net/job/put-shared/job/light/job/logstash.svg?label=put-shared)](https://doi-janky.infosiftr.net/job/put-shared/job/light/job/logstash/) |
 
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