Added file tabs, refined CSS, updated Windows screenshots

.github/ISSUE_TEMPLATE/feature_request.md

@@ -7,6 +7,9 @@ assignees: 'ransome1'
 
 ---
 
+*If your proposal is more a rough idea than a precise description of a feature, please consider starting a discussion instead: https://github.com/ransome1/sleek/discussions
+Please only continue the feature request if you have a precise idea of what you're asking for and if you can provide specific details, use cases or examples. 
+
 **Did you check if a similar feature request has already been reported?**
 Please do so first: https://github.com/ransome1/sleek/issues
 

README.md

@@ -77,7 +77,7 @@ A prioritized backlog of new features and known issues can be found <a href="htt
   - contexts
   - projects
   - due dates
-  - start dates
+  - creation dates
   - <a href="https://github.com/ransome1/sleek/wiki/Recurring-todos-(rec:)">recurrences</a>
   - <a href="https://github.com/ransome1/sleek/wiki/Deferred-todos-(t:)">thresholds</a>
 * Todo-List can be grouped and sorted by priorities, due dates, contexts or projects