set the linguist settings up so that github treats vcpkg as a C++
project (basically, ignore /ports)

* define line endings for ci.baseline.txt

* renormalize line endings to lf

If you experience trouble, you can use the following to renormalize your local working directory:

git add --renormalize .
git reset .
git checkout .

Restrict policy consumers to a simpler interface than std::map.
Rename vcpkg::getMachineType -> vcpkg::to_machine_type.