Updates issue templates

- Updates bug report template;
- Adds suggestion template;

.github/ISSUE_TEMPLATE/bug_report.md

@@ -3,18 +3,21 @@ name: Bug report
 about: Create a report to help us improve
 title: ''
 labels: new issue
-assignees: miguelpruivo
 
 ---
 
+Before creating an issue, make sure that you are on the latest `file_picker` version and that there aren't already any similar opened inssues. Also, check if it isn't described on the [Wiki](https://github.com/miguelpruivo/flutter_file_picker/wiki), specially on [Troubleshooting](https://github.com/miguelpruivo/flutter_file_picker/wiki/Troubleshooting) page.
+
+Also, sometimes a simple `flutter clean` and `flutter build` again with latest file_picker version, may end up by fixing cached issues, so I encourage you to first do so.
+
 **Describe the bug**
 A clear and concise description of what the bug is. If the issue happens to be on Android, please make sure that it also happens with a different device/simulator and/or version.
 
 **Issue details**
 1. Platform (Android/iOS)
-2. OS version
-3. File type (filter)
-4. Steps to reproduce
+2. Platform OS version
+3. File type (filter) — when applicable
+4. Detailed steps to reproduce
 
 **Error Log**
 Please, post the _full_ console log of your issue, if applicable.

.github/ISSUE_TEMPLATE/suggestion.md

@@ -0,0 +1,11 @@
+---
+name: Suggestion
+about: Add a new suggestion
+title: ''
+labels: suggestion
+
+---
+
+I encourage you to add new suggestions that you think that can make file_picker even a better package.
+
+_**Note:**_: Before creating a new suggestion, make sure it isn't already listed. Filter by [suggestion] tag.