🚧Add notes about Ubuntu to README

[CalvinWilkinson]

Complete The Item Below

• I have updated the title without removing the 🚧 emoji.

Description

Update the README.md file by adding the following Quick Note section. This text is about notifying the user that the action must be used in a job that runs on Ubuntu, not Windows.
Insert the markdown in between the What is it? and Quick Example sections.

Markdown to add:

<div align="center"><h3 style="font-weight:bold">⚠️Quick Note⚠️</h3></div>

This GitHub action is built using C#/NET and runs in a docker container.  If the job step for running this action is contained in a job that runs on **Windows**, you will need to move the step to a job that runs on **Ubuntu**.  You can split up your jobs to fulfill `runs-on` requirements of the GitHub action. This can be accomplished by moving the step into it's own job.  You can then route the action step outputs to the job outputs and use them throughout the rest of your workflow. For more information, refer to the Github documentation links below:

For more info on step and job outputs, refer to the GitHub documentation links below:
- [Defining outputs for jobs](https://docs.github.com/en/actions/using-jobs/defining-outputs-for-jobs)
- [Setting a step action output parameter](https://docs.github.com/en/actions/using-workflows/workflow-commands-for-github-actions#setting-an-output-parameter)

Old section to replace:

Acceptance Criteria

• README file updated

ToDo Items

• Change type labels added to this issue. Refer to the Change Type Labels section below.
• Priority label added to this issue. Refer to the Priority Type Labels section below.
• Issue linked to the correct project (if required).
• Issue linked to the correct milestone (if required).
• Draft pull request created and linked to this issue (only required with code changes).

Issue Dependencies

No response

Related Work

No response

Additional Information:

Change Type Labels

Change Type	Label
Bug Fixes	🐛bug Something isn't working
Breaking Changes	🧨breaking changes Feature/changes contains breaking changes
New Feature	✨new feature New feature that does not exist
Workflow Changes	https://github.com/KinsonDigital/BranchValidator/labels/workflow
Code Doc Changes	📑documentation/code Code documentation changes in source code. XML code docs/comments
Product Doc Changes	📝documentation/product Product documentation external to source code. Doc website

Priority Type Labels

Priority Type	Label
Low Priority	low priority Low Priority
Medium Priority	medium priority Medium Priority
High Priority	high priority High Priority

Code of Conduct

• I agree to follow this project's Code of Conduct.