chore: update echo example (#734)

Author: bradydean

examples/integration-echo/main.go

@@ -15,9 +15,14 @@ func main() {
 
 // This custom Render replaces Echo's echo.Context.Render() with templ's templ.Component.Render().
 func Render(ctx echo.Context, statusCode int, t templ.Component) error {
-	ctx.Response().Header().Set(echo.HeaderContentType, echo.MIMETextHTML)
-	ctx.Response().Writer.WriteHeader(statusCode)
-	return t.Render(ctx.Request().Context(), ctx.Response().Writer)
+	buf := templ.GetBuffer()
+	defer templ.ReleaseBuffer(buf)
+
+	if err := t.Render(ctx.Request().Context(), buf); err != nil {
+		return err
+	}
+
+	return ctx.HTML(statusCode, buf.String())
 }
 
 func HomeHandler(c echo.Context) error {