Add data ingestion use case using Cosmosdb output binding

This sample currently shows comprehensive use of the CosmosDb Trigger.

I want to add a feature showing data ingestion from http, which will leverage http trigger + cosmosdb output binding.

Use this [e2e SQL example](https://github.com/Azure-Samples/functions-quickstart-python-azd-sql) as the inspiration for the use cases and architecture, but of course stick to using the cosmosdb implementation.

You must make the simplest change possible to add the data ingestion to cosmosdb. The bicep and other files should already work. Use [this documentation](https://learn.microsoft.com/en-us/azure/azure-functions/functions-bindings-cosmosdb-v2-output?tabs=python-v2%2Cisolated-process%2Cnodejs-v4%2Cextensionv4&pivots=programming-language-python) for snippets and reference on cosmosdb output binding.

Please update the readme and diagram as well.