Adding visualization guide for RNA-seq data

[RubabBhatti]

This pull request adds a new "Visualization.rst" file for visualization of RNA-seq data in Integrated Genome Browser (IGB). Also updated index.rst to include the new guide in documentation structure.

Thank you for reviewing my contribution. Let me know if any changes are required.

[RubabBhatti]

Hi Foerstner Lab team!

I hope you're doing well. I wanted to follow up on my PR#69 for adding a visualization guide for RNA-seq data to the READemption pipeline.
I'm excited about the potential of this contribution and would be happy to make any adjustments needed. Could you please let me know if you've had a chance to review my PR?

Thank you for your time, and I look forward to hearing from you.

Best regards,
Kaneez Rubab

[Tillsa]

Dear Kaneez Rubab,

While we appreciate your work on this guide for viewing WIG files in the IGB browser, we believe that the READemption documentation is not the right place to include this information. Our goal is to document READemption itself, rather than other tools. Adding detailed information about external tools would increase the maintenance burden of the READemption documentation (for example, we would need to update it whenever IGB changes and keep track of those updates).

Therefore, we unfortunately have to decline this specific pull request. Please feel free to reach out if you’d like to contribute improvements directly related to the READemption documentation itself.

Best regards,
Till