Setup: Auto-link from GitHub to Jira tickets
GitHub itself does not linkify text like "ICU-23456" to point to the Jira ticket. You can get links via browser extensions.
Chrome Jira HotLinker
Install the Jira HotLinker from the Chrome Web Store.
Jira instance url: https://unicode-org.atlassian.net/
Safari extension from SRL
Firefox extension from JefGen
Install from the Mozilla Firefox Add-ons site: