docs(ISSUE_TEMPLATE): correct labels

Author: bearomorphism

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -1,7 +1,7 @@
 name: 🛠 Bug report
 description: Create a report to help us improve
 title: Good bug title tells us about precise symptom, not about the root cause.
-labels: [bug]
+labels: ['type: bug']
 body:
   - type: textarea
     id: description

.github/ISSUE_TEMPLATE/documentation.yml

@@ -1,7 +1,7 @@
 name: 📖 Documentation
 description: Suggest an improvement for the documentation of this project
 title: Content to be added or fixed
-labels: [documentation]
+labels: ['type: documentation']
 body:
   - type: checkboxes
     id: type

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -1,7 +1,7 @@
 name: 🚀 Feature request
 description: Suggest an idea for this project
 title: "<One feature request per issue>"
-labels: [feature]
+labels: ['type: feature']
 body:
   - type: textarea
     id: description