samples: doc: Added README for RTIO sample

[michalpiekos]

Added README.rst for sensor_batch_processing sample. Added rtio.rst listing samples from RTIO subsystem.
Helps fix #27805

[github-actions]

Hello @michalpiekos, and thank you very much for your first pull request to the Zephyr project!
Our Continuous Integration pipeline will execute a series of checks on your Pull Request commit messages and code, and you are expected to address any failures by updating the PR. Please take a look at our commit message guidelines to find out how to format your commit messages, and at our contribution workflow to understand how to update your Pull Request. If you haven't already, please make sure to review the project's Contributor Expectations and update (by amending and force-pushing the commits) your pull request if necessary.
If you are stuck or need help please join us on Discord and ask your question there. Additionally, you can escalate the review when applicable. 😊

[kartben]

thanks for this! some minor typos or grammar corrections

[kartben]

a typo + changing wording to follow same style as other samples (https://github.com/zephyrproject-rtos/zephyr/blob/main/doc/templates/sample.tmpl#L5-L6)

Suggested change

	Implements sensor device using RTIO for asynchronuous data processing.
	Implement a sensor device using RTIO for asynchronous data processing.

[michalpiekos]

Fixed

[kartben]

same typo :) + suggested wording improvement

Suggested change

	This sample application demonstrates the use of the :ref:`rtio` library
	which is a framework for doing asynchronuous operation chains.
	This sample application demonstrates the use of the :ref:`rtio` framework for
	doing asynchronuous operation chains.

[michalpiekos]

Fixed

[kartben]

Suggested change

	When running the output on the console shows the operations of
	submitting for, consuming and processing the sensor data.
	When running, the output on the console shows the operations of
	submitting for, consuming, and processing the sensor data.

[michalpiekos]

Fixed

[kartben]

Suggested change

	:name: Real Time I/O
	:name: Real Time I/O (RTIO)

[michalpiekos]

Fixed

[github-actions]

Hi @michalpiekos!
Congratulations on getting your very first Zephyr pull request merged 🎉🥳. This is a fantastic achievement, and we're thrilled to have you as part of our community!

To celebrate this milestone and showcase your contribution, we'd love to award you the Zephyr Technical Contributor badge. If you're interested, please claim your badge by filling out this form: Claim Your Zephyr Badge.

Thank you for your valuable input, and we look forward to seeing more of your contributions in the future! 🪁