[cxx-interop] Added an intro to Swift/C++ interoperability article (#90853)
Adds a new DocC article that walks developers through the process of
using Swift/C++ interoperability with Swift Package Manager,
Command-line, and Xcode. The article covers all three development tools
so regardless of the reader's platform, they can follow along.
The running example bridges a C++ class named Error, which collides with
Swift's own Error type and renames it to
CxxErrorExample as it crosses into Swift using the SWIFT_NAME macro from
swift/bridging. This demonstrates how to
reshape a C++ API so it reads like Swift instead of clashing with
existing types.
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Co-authored-by: Joey Brinker <brinkerjoey@outlook.com>
Co-authored-by: Colleen Toporek <colleenish@gmail.com>
Co-authored-by: Chris Adamson <invalidname@gmail.com>