Revise GitHub templates

- Separate templates into bug report and feature request
- Add a checklist and guidance comments
- Add a PR template
- Add SUPPORT.md

.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,61 @@
+---
+name: Feature Request
+about: Suggest a new feature or enhancement for qBittorrent.
+title: ''
+labels: 'Feature request'
+assignees: ''
+---
+
+# Feature request
+
+<!--
+###############################################################################
+  WARNING!
+  IGNORING THE INSTRUCTIONS IN THIS TEMPLATE WILL RESULT IN THE ISSUE BEING
+  CLOSED AS INCOMPLETE/INVALID
+###############################################################################
+-->
+
+## Checklist
+
+<!--
+################################## IMPORTANT ##################################
+
+As you read and fulfill each of the following requirements below,
+put an "x" between the square brackets to mark each task as done, like so: [x]
+-->
+
+- [ ] I have read the **feature request section** in the [contributing guidelines](https://github.com/qbittorrent/qBittorrent/blob/master/CONTRIBUTING.md), so I know how to submit a good feature request with the required information
+- [ ] I have verified that the **feature** I am requesting is **not available** in the **[latest version](https://www.qbittorrent.org/download.php)**
+- [ ] (optional but recommended) I have verified that the **feature** I am requesting is **not available** in the **[latest CI build](https://github.com/qbittorrent/qBittorrent/actions/workflows/ci.yaml?query=branch%3Amaster+event%3Apush)**
+- [ ] I have **checked the [frequent/common issues list](https://github.com/qbittorrent/qBittorrent/projects/2)** and **searched** the issue tracker for similar feature requests (including closed ones) **to avoid posting a duplicate**
+- [ ] This request is **not a support request or question**, both of which are better suited for either the [discussions section](https://github.com/qbittorrent/qBittorrent/discussions), [forum](https://qbforums.shiki.hu/), or [subreddit](https://www.reddit.com/r/qBittorrent/). The [wiki](https://github.com/qbittorrent/qBittorrent/wiki) did not contain a suitable solution either
+
+## Description
+
+<!--
+################################## IMPORTANT ##################################
+
+Delete each "(type here)" indicator and type your text in their place in the subsections below.
+You MUST fill in ALL subsections marked with "(type here)" with the appropriate information.
+
+Please make sure the description is worded well enough to be understood.
+Provide a detailed description of the feature and as much context and examples as necessary.
+If the feature request has to do with visual elements and the GUI, images/screenshots are always helpful.
+For more information consult the Contributing Guidelines at https://github.com/qbittorrent/qBittorrent/blob/master/CONTRIBUTING.md.
+
+Use the Preview tab before posting to make sure your report looks like it is formatted properly.
+You don't need to delete these comments, they won't show up in the final post.
+-->
+
+### Suggestion
+
+(type here)
+
+### Use case
+
+(type here)
+
+### Extra info/examples/attachments
+
+<!-- optional -->