Insufficient documentation to get a basic get_flight_info() working

**Describe the bug**

Python has this [cookbook](https://arrow.apache.org/cookbook/py/flight.html). C++ has one too. There are many blog posts on this topic.

But I couldn't find one for Rust.

**To Reproduce**

Run the steps in the README here:

https://github.com/adsharma/ashdb/tree/in_memory_kv

It's a toy kv store backed by a hashmap. I get:

```
./target/debug/flight_sql_client --host localhost --port 50051 db-schemas %
Error: read flight data

Caused by:
0: collect data stream
1: Decode error: Error decoding root message: Type `i32` at position 1818585414 is unaligned.
```

**Expected behavior**

Successful listing of schemas.

Start with the ashdb README on the in_memory_kv branch and reproduce the flight_sql_client get_flight_info and schema-listing steps. Compare the Rust guidance with the linked Python and C++ Flight cookbooks. Done means the Rust documentation provides a basic working get_flight_info example and the schema listing succeeds without the decoding error.

Written by the indexing model from the issue text.