Improve the issue templates

.github/ISSUE_TEMPLATE/feature_request.md

@@ -7,24 +7,29 @@ labels: enhancement
 <!-- NOTE: Please maintain all sections, otherwise the issue will be automatically closed :) -->
 
 ## Checklist
+
 <!-- Please complete the following list of tasks, and then check it by changing the "[ ]" to "[x]" -->
 - [ ] I have read the [contributing guidelines](https://github.com/cotes2020/jekyll-theme-chirpy/blob/master/.github/CONTRIBUTING.md).
-- [ ] There is no similar request on existing issues (including closed ones).
+- [ ] There is no similar request on [existing issues](https://github.com/cotes2020/jekyll-theme-chirpy/issues?q=is%3Aissue) (including closed ones).
 - [ ] I have read the [project progress](https://github.com/cotes2020/jekyll-theme-chirpy/projects) and know the current progress of the project.
 - [ ] I was in the `master` branch of the latest code.
 
 
 ## Is your feature request related to a problem? Please describe
+
 <!-- A clear and concise description of what the problem is. Ex. I'm always frustrated when [...] -->
 
 
 ## Describe the solution you'd like
+
 <!-- A clear and concise description of what you want to happen. -->
 
 
 ## Describe alternatives you've considered
+
 <!-- A clear and concise description of any alternative solutions or features you've considered. -->
 
 
 ## Additional context
+
 <!-- Add any other context or screenshots about the feature request here. -->