Mark most fields in the bug report form as mandatory

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -12,26 +12,36 @@ body:
       label: What happened?
       description: Also tell us, what did you expect to happen?
       placeholder: Tell us what you see!
+    validations:
+      required: true
   - type: textarea
     attributes:
       label: Configuration file
       description: Please copy and paste your machine configuration file (`86box.cfg`). This will be automatically formatted into code, so no need for backticks.
       render: ini
+    validations:
+      required: true
   - type: input
     attributes:
       label: Operating system
       description: What is your host operating system?
       placeholder: e.g. Windows 10
+    validations:
+      required: true
   - type: input
     attributes:
       label: CPU
       description: What is your host CPU?
       placeholder: e.g. AMD Ryzen 5 5600G
+    validations:
+      required: true
   - type: input
     attributes:
       label: 86Box version
       description: What version of 86Box are you running? (Saying "Latest from Jenkins" is not helpful.)
       placeholder: e.g. v4.0 build 5000
+    validations:
+      required: true
   - type: dropdown
     attributes:
       label: Build architecture
@@ -44,6 +54,8 @@ body:
         - macOS - Universal (Intel and Apple Silicon) 
         - Windows - x64 (64-bit) 
         - Windows - x86 (32-bit)
+    validations:
+      required: true
   - type: checkboxes
     attributes:
       label: Build type
@@ -60,6 +72,8 @@ body:
         - Manager auto-update
         - I built 86Box myself (please tell us more about your build configuration)
         - I got 86Box from a third party repository (please tell us where)
+    validations:
+      required: true
   - type: textarea
     attributes:
       label: Additional context