Summary:
The commands as they were previously would attempt to install Folly as 32-bit, which would fail.
Also removes an extra `-` in the link's url.
Closes: https://github.com/facebook/folly/issues/713
Reviewed By: yfeldblum
Differential Revision:
D6327981
fbshipit-source-id:
ced8c86948b8be5c1dd88e14d6c3a77fc783aac9
#### Windows (Vcpkg)
-folly is available in [Vcpkg](https://github.com/Microsoft/vcpkg#vcpkg-) and releases may be built via `vcpkg install folly`.
+folly is available in [Vcpkg](https://github.com/Microsoft/vcpkg#vcpkg) and releases may be built via `vcpkg install folly:x64-windows`.
-You may also use `vcpkg install folly --head` to build against `master`.
+You may also use `vcpkg install folly:x64-windows --head` to build against `master`.
#### Other Linux distributions