Update templates and remove unused assets

Enhanced the issue and pull request templates for better clarity and structure. Removed the CHANGELOG.md file and several unused image assets from the repository to clean up project files.

Author: mazino2d

.github/issue_template.md

@@ -1,3 +1,35 @@
-Please only submit feature suggestions or bug reports if you believe something is broken.
+# Issue Template
 
-If you need help, you can attend the [Office Hours](https://beautifuljekyll.com/officehours) (only available for [sponsors](https://beautifuljekyll.com/plans/)).
+## Issue Type
+
+- [ ] Bug Report
+- [ ] Feature Request
+- [ ] Documentation
+- [ ] Question
+
+## Description
+<!-- Provide a clear and concise description of the issue or feature request -->
+
+## Steps to Reproduce (for bugs)
+
+1.
+2.
+3.
+
+## Expected Behavior
+<!-- What did you expect to happen? -->
+
+## Actual Behavior
+<!-- What actually happened? -->
+
+## Environment
+
+- **OS:**
+- **Browser:**
+- **Jekyll version:**
+
+## Screenshots
+<!-- If applicable, add screenshots to help explain the issue -->
+
+## Additional Context
+<!-- Add any other context about the problem here -->

.github/pull_request_template.md

@@ -1,3 +1,5 @@
+# Pull Request Template
+
 ## Description
 <!-- Brief description of changes in this PR -->
 
@@ -11,6 +13,7 @@
 - [ ] Other (describe below)
 
 ## Checklist
+
 - [ ] Tested preview locally (`bundle exec jekyll serve`)
 - [ ] Checked spelling and grammar
 - [ ] Optimized images (if applicable)