Add subscript to issue templates (#3669)

Co-authored-by: otelbot <[email protected]>

Author: opentelemetrybot

.github/ISSUE_TEMPLATE/bug_report.yaml

@@ -64,3 +64,11 @@ body:
       options:
         - "No"
         - "Yes"
+
+  - type: dropdown
+    attributes:
+      label: Tip
+      description: This element is static, used to render a helpful sub-heading for end-users and community members to help prioritize issues. Please leave as is.
+      options:
+        - <sub>[React](https://github.blog/news-insights/product-news/add-reactions-to-pull-requests-issues-and-comments/) with 👍 to help prioritize this issue. Please use comments to provide useful context, avoiding `+1` or `me too`, to help us triage it. Learn more [here](https://opentelemetry.io/community/end-user/issue-participation/).</sub>
+      default: 0

.github/ISSUE_TEMPLATE/feature_request.yaml

@@ -48,3 +48,11 @@ body:
       options:
         - "No"
         - "Yes"
+
+  - type: dropdown
+    attributes:
+      label: Tip
+      description: This element is static, used to render a helpful sub-heading for end-users and community members to help prioritize issues. Please leave as is.
+      options:
+        - <sub>[React](https://github.blog/news-insights/product-news/add-reactions-to-pull-requests-issues-and-comments/) with 👍 to help prioritize this issue. Please use comments to provide useful context, avoiding `+1` or `me too`, to help us triage it. Learn more [here](https://opentelemetry.io/community/end-user/issue-participation/).</sub>
+      default: 0