Add release note instructions to issue template. (dapr#360)

Author: artursouza

.github/ISSUE_TEMPLATE/bug_report.md

@@ -19,3 +19,14 @@ assignees: ''
 ## Steps to Reproduce the Problem
 
 <!-- How can a maintainer reproduce this issue (be detailed) -->
+
+## Release Note
+
+<!-- How should the fix for this issue be communicated in our release notes? It can be populated later. -->
+<!-- Keep it as a single line. Examples: -->
+
+<!-- RELEASE NOTE: **ADD** New feature in Dapr. -->
+<!-- RELEASE NOTE: **FIX** Bug in runtime. -->
+<!-- RELEASE NOTE: **UPDATE** Runtime dependency. -->
+
+RELEASE NOTE:

.github/ISSUE_TEMPLATE/feature_request.md

@@ -7,3 +7,13 @@ assignees: ''
 
 ---
 ## Describe the feature
+
+## Release Note
+<!-- How should this new feature be announced in our release notes? It can be populated later. -->
+<!-- Keep it as a single line. Examples: -->
+
+<!-- RELEASE NOTE: **ADD** New feature in Dapr. -->
+<!-- RELEASE NOTE: **FIX** Bug in runtime. -->
+<!-- RELEASE NOTE: **UPDATE** Runtime dependency. -->
+
+RELEASE NOTE: