[DOC] Uninstall instructions for each platform

[anjannath]

We have different uninstall steps for each platform.

For macOS: User needs to run crc cleanup -> rm -rf /usr/local/crc
For windows: run crc cleanup and uninstall OpenShift Local from Control Panel -> Add/Remove Programs
For linux: crc cleanup and rm -rf $(which crc)

[a1ex-var1amov]

For MacOS:

• crc cleanup
• sudo rm -rf /usr/local/crc
• rm -rf ~/.crc/

[davidkhala]

crc cleanup is just for Undo config changes

crc delete should be included for deleting the instance