[docs] Delete embedded documentation in favor of docs/

[ras0219-msft]

After discussion, we've determined that maintaining the documentation inside the port where fixing typos requires republishing the port, is problematic.

This PR performs one final regenerate run (including the missing port helpers vcpkg-qmake and vcpkg-get-python-modules) and then purges all embedded documentation in the script helpers and port helpers.

This PR does not touch any of the content of this documentation -- that will be done in follow-up PRs.

Drive-by for the helper ports:

1. "documentation": "https://vcpkg.io/en/docs/README.html"
2. "license": "MIT"
3. Use include_guard(GLOBAL) in all script files
4. Make sure any persistent variables are saved to the cache

[Neumann-A]

strictly speaking you cannot have the docs of scripts ports in docs/ since the docs probably depend on the version which gets installed.

[ras0219-msft]

We did discuss that as well (it was one of my concerns).

Our approach moving forward will be to include "Added in version x-y-z" annotations where appropriate in future documentation changes. We won't be "backdating" any existing documentation.

[BillyONeal]

Rather than adding an empty regenerate.ps1 can you just delete this block that was calling it?

vcpkg/scripts/azure-pipelines/windows/azure-pipelines.yml

Lines 49 to 56 in 203f5f3

	# Note that we run docs checks before PR checks because they are likely to invalidate a whole run anyway
	- task: Powershell@2
	displayName: 'Generate Documentation'
	condition: eq('${{ parameters.triplet }}', '${{ variables.ExtraChecksTriplet }}')
	inputs:
	filePath: 'docs/regenerate.ps1'
	arguments: '-VcpkgRoot . -WarningAction Stop'
	pwsh: true

[ras0219-msft]

I'm going to go ahead and merge since the previous c645bad passed.

[dg0yt]

From draft to world rebuild in less than 24 hours... But I'm glad this documentation update barrier is removed.