Update PULL_REQUEST_TEMPLATE.md (#606)

Author: sashabaranov

.github/PULL_REQUEST_TEMPLATE.md

@@ -8,11 +8,14 @@ Thanks for submitting a pull request! Please provide enough information so that
 **Describe the change**
 Please provide a clear and concise description of the changes you're proposing. Explain what problem it solves or what feature it adds.
 
+**Provide OpenAI documentation link**
+Provide a relevant API doc from https://platform.openai.com/docs/api-reference
+
 **Describe your solution**
 Describe how your changes address the problem or how they add the feature. This should include a brief description of your approach and any new libraries or dependencies you're using.
 
 **Tests**
-Briefly describe how you have tested these changes. 
+Briefly describe how you have tested these changes. If possible — please add integration tests.
 
 **Additional context**
 Add any other context or screenshots or logs about your pull request here. If the pull request relates to an open issue, please link to it.