ci: add GitHub Actions workflows for upstream sync and release automation

tests/e2e/output/converters/pandoc/input.md

@@ -0,0 +1,22 @@
+# Test Document
+
+This is a **test** document for E2E testing.
+
+## Code Example
+
+```javascript
+console.log("Hello, World!");
+```
+
+## List
+
+1. First item
+2. Second item
+3. Third item
+
+## Table
+
+| Name | Value |
+|------|-------|
+| A    | 1     |
+| B    | 2     |