fix: using code blocks within release-notes (#275)

Increase the number of code blocks backticks to 4 for the release note prefix and suffix, to allow users to embed their own code blocks using only 3 backticks.

internal/testdata/testdata.go

@@ -0,0 +1,19 @@
+package testdata
+
+import (
+	"embed"
+	"testing"
+)
+
+//go:embed *.txt
+var testdata embed.FS
+
+func MustReadFileString(t *testing.T, name string) string {
+	t.Helper()
+
+	content, err := testdata.ReadFile(name)
+	if err != nil {
+		t.Fatal(err)
+	}
+	return string(content)
+}