chore: add new feature template

.github/ISSUE_TEMPLATE/add-new-feature---behavior.md

@@ -0,0 +1,42 @@
+---
+name: Add new feature / behavior
+about: Describe the desired product feature
+title: 'Ex: Add AWS RDS Postgresql datasource support'
+labels: ''
+assignees: ''
+
+---
+
+## Scope & Context
+
+**Example:**
+```
+We are working on AWS Appsync API that uses AWS RDS Postgresql.
+The current serverless-appsync-plugin does not support RDS as a datasource.
+```
+
+## Current behavior
+
+A clear and concise description of what the current behavior is.
+
+**Example:**
+```
+Currently, AWS RDS Postgresql is not supported as datasource.
+```
+
+## Expected behavior
+A clear and concise description of what you want to happen.
+Please also add **AWS documentation** if available
+
+**Example:**
+```
+AWS RDS Postgresql is supported as datasource for queries or mutations.
+```
+
+## Technical inputs
+
+**Example:**
+```
+- Extend **datasource** configuration with fields ...
+- Add a new service ...
+```