Add subscript to issue templates (#2586)

Co-authored-by: otelbot <197425009+otelbot@users.noreply.github.com>

.github/ISSUE_TEMPLATE/bug_report.yaml

@@ -110,3 +110,10 @@ body:
     attributes:
       label: Describe the solution you'd like
       description: A clear and concise description of solution you'd like to see.
+  - 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/change_proposal.yaml

@@ -101,3 +101,10 @@ body:
     attributes:
       label: Describe the solution you'd like
       description: A clear and concise description of solution you'd like to see.
+  - 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/new-conventions.yaml

@@ -113,3 +113,10 @@ body:
         conventions and the benefits they would bring to the ecosystem.
     validations:
       required: true
+  - 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