Update issue templates

Author: tuoping

.github/ISSUE_TEMPLATE/feature-request.md

@@ -3,7 +3,7 @@ name: Feature request
 about: Suggest an idea for this project. If this doesn’t work right, [choose a different
   type]( https://github.com/deepmodeling/deepmd-kit/issues/new/choose)
 title: "[Feature Request] _Replace with Title_"
-labels: ''
+labels: enhancement
 assignees: ''
 
 ---

.github/ISSUE_TEMPLATE/parameters.md

@@ -3,7 +3,7 @@ name: Parameters
 about: Make a suggestion for a change of input parameters or a new output to deepmd-kit.
   If this doesn’t work right, [choose a different type]( https://github.com/deepmodeling/deepmd-kit/issues/new/choose).
 title: "[Parameters] _Replace With Suitable Title_"
-labels: enhancement
+labels: documentation, enhancement
 assignees: ''
 
 ---