Remove issue prefixes

Author: haydenbleasel

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -1,6 +1,6 @@
 name: Bug Report
 description: Report a bug or unexpected behavior in Streamdown
-title: "[Bug]: "
+title: ""
 labels: ["bug", "needs-triage"]
 body:
   - type: markdown

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -1,6 +1,6 @@
 name: Feature Request
 description: Suggest a new feature or enhancement for Streamdown
-title: "[Feature]: "
+title: ""
 labels: ["enhancement", "needs-triage"]
 body:
   - type: markdown