allow rustdoc::unportable_markdown in arrow-flight.

Author: Rachelint

arrow-flight/src/lib.rs

@@ -37,6 +37,7 @@
 //!
 //! [Flight SQL]: https://arrow.apache.org/docs/format/FlightSql.html
 #![allow(rustdoc::invalid_html_tags)]
+#![allow(rustdoc::unportable_markdown)]
 
 use arrow_ipc::{convert, writer, writer::EncodedData, writer::IpcWriteOptions};
 use arrow_schema::{ArrowError, Schema};