Clarify instructions in README.md

[luisdev]

The README.md file gives these instructions:

1. Download installer zip
2. Extract all files in zip file to same directory

Please clarify WHERE you should extract the zip file to. Must it be somewhere in your \wsl$ Linux directory or do you extract it to your local Windows C:\ drive?

And what happens when you run RHWSL.exe? Does it automatically install Red Hat into your \wsl$ directory?

Please clarify the installation instructions so that they are clear to even WSL and Linux beginners.

[strushb]

Extract the files to a writable directory, this depends on whether you are in a corporate environment or not. When you run RHWSL.exe, it will extract the rootfs.tar.gz into a new directory in the same path, so this should not be something like "Downloads", Temp directory or the like.

C:\RHWSL or C:\Program Files\Red Hat WSL would be good options

[ScottHutchinson]

What is a UBI? Never mind, I see it now "Universal Base Image" in the middle of the readme.

I extracted the files from the .zip file, but I don't see any RHWSL.exe file. How do I get that file? Never mind. See #4

When and where do I run the wsl --set-version RHWSL 2 command? Ok, I ran it in the Windows command prompt or Powershell terminal, and it worked.

Thank you so much for providing this easy way to install RHEL on WSL!