feat: add issues field for theme manifest (#146)

为 theme.yaml 添加 issues 字段，适配：halo-dev/halo#5755 /kind improvement ```release-note 为 theme.yaml 添加 issues 字段 ```
halo-dev · Apr 28, 2024 · 689e6a3 · 689e6a3
1 parent e847e95
commit 689e6a3
Showing 1 changed file with 1 addition and 0 deletions.
diff --git a/theme.yaml b/theme.yaml
@@ -15,6 +15,7 @@ spec:
   logo: https://www.halo.run/logo
   homepage: https://www.halo.run/store/apps/app-KgWqR
   repo: https://github.com/halo-dev/theme-earth
+  issues: https://github.com/halo-dev/theme-earth/issues
   settingName: "theme-earth-setting"
   configMapName: "theme-earth-configMap"
   version: 1.8.0