Create release-checklist.md

A release checklist template for maintainers

Signed-off-by: Appu <[email protected]>

Author: loosebazooka

.github/ISSUE_TEMPLATE/release-checklist.md

@@ -0,0 +1,22 @@
+---
+name: Release Checklist
+about: All the tasks required to complete a release of sigstore-java and maven/gradle plugins
+title: Release v<fill in>
+labels: ''
+assignees: ''
+
+---
+
+Full release instructions are at: [RELEASING.md](/sigstore/sigstore-java/blob/main/RELEASING.md)
+
+## Tag Release
+- [ ] `v<version>`
+
+## Publish Release
+- [ ] `sigstore-java`, `sigstore-maven-plugin` to Maven Central ([action](https://github.com/sigstore/sigstore-java/actions/workflows/release-sigstore-java-from-tag.yaml))
+- [ ] `sigstore-gradle-plugin` to Gradle Plugin Portal ([action](https://github.com/sigstore/sigstore-java/actions/workflows/release-sigstore-gradle-plugin-from-tag.yaml))
+
+## Verify Releases Published
+- [ ] [sigstore-java](https://repo1.maven.org/maven2/dev/sigstore/sigstore-java)
+- [ ] [sigstore-maven-plugin](https://repo1.maven.org/maven2/dev/sigstore/sigstore-maven-plugin)
+- [ ] sigstore-gradle-plugin [[base](https://plugins.gradle.org/plugin/dev.sigstore.sign-base)], [[sign](https://plugins.gradle.org/plugin/dev.sigstore.sign)]