Fix instance issue template

.github/ISSUE_TEMPLATE/new_instance.yaml

@@ -4,7 +4,7 @@ title: "[New instance] <instance name>"
 assignees: ''
 
 body:
-- type: checkboxes
+  - type: checkboxes
     attributes:
       label: Mandatory checks
       description: "Your instance must fulfill all the conditions listed below in order to be accepted"
@@ -16,16 +16,17 @@ body:
       - label: "Statistics (`/api/v1/stats`) are enabled"
         required: true
 
-- type: checkboxes
+  - type: checkboxes
     attributes:
       label: Maintainer chart
       description: "As a maintainer, I acknowledge that I must do the following to stay in the public list"
+      options:
       - label: "Ensure that my instance is up to date (less than one month old)"
         required: true
       - label: "Ensure a proper uptime of my instance (around 90%)"
         required: true
 
-- type: input
+  - type: input
     id: mitm-name
     attributes:
       label: Man in the Middle
@@ -34,7 +35,7 @@ body:
     validations:
       required: false
 
-- type: input
+  - type: input
     id: source-code-url
     attributes:
       label: Source code URL
@@ -43,7 +44,7 @@ body:
     validations:
       required: false
 
-- type: checkboxes
+  - type: checkboxes
     attributes:
       label: Analytics
       description: "If your instance is running analytics:"