Touch handler: remove Windows 8 checks from code and documentation (#15642)
Closes #15635
Summary of the issue:
Touch handler's touchSupported function and the user guide continues to check (or document requirement) for Windows 8 when minimum OS is Windows 8.1.
Description of user facing changes
Edited the user guide and context help to point out that touch support requires a touch-capable hardware and that NVDA must be installed, removing wording on Windows 8 requirement.
Description of development approach
Edit touchHandler.touchSupported function to remove check for Windows 8 as Windows 8.1 is the minimum OS required, as wel as edited parts of the user guide dealing with touch support.