chore: update pr template to improve doc control

.github/pull_request_template.md

@@ -33,19 +33,28 @@ This pull request is in the type of:
 
 
 
-### After: How is it fixed in this PR?
+### After: How does it behave after the fixing?
 
 <!-- THE RESULT AFTER FIXING AND A SIMPLE EXPLANATION ABOUT HOW IT IS FIXED. -->
 
 <!-- ADD SCREENSHOT HERE IF APPLICABLE. -->
 
 
 
+## Document Info
+
+One of the following should be checked.
+
+- [ ] This PR doesn't relate to document changes
+- [ ] The document should be updated later
+- [ ] The document changes have been made in apache/echarts-doc#xxx
+
+
+
 ## Misc
 
-<!-- ADD RELATED ISSUE ID WHEN APPLICABLE -->
+### ZRender Changes
 
-- [ ] The API has been changed (apache/echarts-doc#xxx).
 - [ ] This PR depends on ZRender changes (ecomfe/zrender#xxx).
 
 ### Related test cases or examples to use the new APIs