Add bug_report.yml (issue templates) (#188)

* Add `bug_report.yml` (issue templates)

- replace `bug_report.md` with bug_report.yml
- automatically assing bug reports to @volterra79 user

* Remove `required` attribute for checkbox

* Update bug_report.yml

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -0,0 +1,62 @@
+name: 🐞 Bug report
+description: Report a bug/issue
+labels: [bug]
+assignees: [volterra79]
+body:
+- type: checkboxes
+  attributes:
+    label: Checklist
+    description: >
+      Please confirm the following:
+    options:
+    - label: I've searched through the existing [issues](https://github.com/g3w-suite/g3w-client/issues) and this bug has never been reported before
+      required: false
+- type: textarea
+  attributes:
+    label: Subject of the issue
+    description: Describe your issue here.
+    placeholder: You can attach images or log files by clicking this area to highlight it and then dragging files in.
+  validations:
+    required: true
+- type: textarea
+  attributes:
+    label: Steps to reproduce
+    description: Steps to reproduce the behavior.
+    placeholder: |
+      1. Go to '...'
+      2. Click on '....'
+      3. Scroll down to '....'
+      4. See error
+  validations:
+    required: true
+- type: textarea
+  attributes:
+    label: Environment
+    description: |
+     Please provide as much information as possible in order to resolve your issue. Need help? [Find out your version](https://github.com/g3w-suite/g3w-admin#version).
+    value: |
+     - g3w-admin: __version__
+     - g3-client: __version__
+     - browser: __name__
+     - operating system: __name and version (desktop or mobile)__
+  validations:
+    required: true
+- type: input
+  attributes:
+    label: Link to your project
+    description: A public URL that can help others to check your issue
+    placeholder: eg. https://dev.g3wsuite.it/en/map/demo-34/
+  validations:
+    required: false
+- type: textarea
+  attributes:
+    label: Additional info
+    description: |
+      Add any other useful information that could allow others to replicate your issue, for example:
+      - **installed plugins**
+      - **project structure**
+      - **configuration files**
+      - **self-explanatory pictures**
+    placeholder: You can attach images or log files by clicking this area to highlight it and then dragging files in.
+  validations:
+    required: false