chore(ISSUE_TEMPLATE): update formatting

.github/ISSUE_TEMPLATE/NEW_RULE.md

@@ -4,26 +4,26 @@ about: Use this template to propose new modeling rules to be included in the lib
 labels: [ "rules" ]
 ---
 
-#### The rule should detect the following modeling patterns
+### The rule detects the following modeling patterns
 
 <!-- please share correct and incorrect usage examples as BPMN files -->
 
 * 
 *
 
-#### How does the rule improve the BPMN diagram?
+### How does the rule improve the BPMN diagram?
 
 <!--
 Describe how people would benefit from this modeling rule. This will be included in the user documentation, cf. https://github.com/bpmn-io/bpmnlint/blob/master/docs/rules/label-required.md.
 -->
 
-#### Rule Details
+### Rule Details
 
 * Name: 
 * Default notification level: `error|warn|off`
 
 
-#### What alternatives did you consider? 
+### What alternatives did you consider? 
 
 <!--
 Describe alternatives to this rule you considered.