Fix syntax

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -13,7 +13,6 @@ body:
     attributes:
       label: Printer model
       description: Enter the printer model(s) where you encountered the issue
-      placeholder: 'MK3S/+, MK3, Mk2.5S, MK2.5'
       options:
         - MK3S/+
         - MK3
@@ -26,11 +25,11 @@ body:
     attributes:
       label: MMU model
       description: Enter the MMU model(s) where you encountered the issue
-      placeholder: 'MMU3, MMU2S'
+      multiple: false
       options:
         - MMU3
         - MMU2S
-      - None
+        - No-MMU
     validations:
       required: true
   - type: input
@@ -53,6 +52,7 @@ body:
     id: printing_from
     attributes:
       label: Printing from...
+      multiple: false
       options:
         - SD Card
         - PrusaLink