Fix typo in cpp.md
Fix typo in cpp.md

Hi,
I fixed a typo in the tree representation of tutorial directories/files at `cpp.md`.

Closes #5276.

PiperOrigin-RevId: 198297573

dslomov/bazel,akira-baruah/bazel,katre/bazel,twitter-forks/bazel,katre/bazel,bazelbuild/bazel,meteorcloudy/bazel,ButterflyNetwork/bazel,twitter-forks/bazel,davidzchen/bazel,ulfjack/bazel,dropbox/bazel,perezd/bazel,aehlig/bazel,werkt/bazel,dslomov/bazel,ButterflyNetwork/bazel,bazelbuild/bazel,cushon/bazel,akira-baruah/bazel,ulfjack/bazel,safarmer/bazel,twitter-forks/bazel,dslomov/bazel-windows,katre/bazel,dropbox/bazel,perezd/bazel,werkt/bazel,twitter-forks/bazel,safarmer/bazel,meteorcloudy/bazel,cushon/bazel,werkt/bazel,dslomov/bazel-windows,safarmer/bazel,aehlig/bazel,aehlig/bazel,dslomov/bazel,safarmer/bazel,akira-baruah/bazel,ButterflyNetwork/bazel,cushon/bazel,dslomov/bazel-windows,ulfjack/bazel,perezd/bazel,meteorcloudy/bazel,ulfjack/bazel,aehlig/bazel,davidzchen/bazel,dslomov/bazel-windows,katre/bazel,aehlig/bazel,perezd/bazel,meteorcloudy/bazel,davidzchen/bazel,cushon/bazel,davidzchen/bazel,ulfjack/bazel,bazelbuild/bazel,perezd/bazel,dslomov/bazel,meteorcloudy/bazel,davidzchen/bazel,dslomov/bazel-windows,katre/bazel,perezd/bazel,akira-baruah/bazel,ButterflyNetwork/bazel,davidzchen/bazel,davidzchen/bazel,akira-baruah/bazel,twitter-forks/bazel,werkt/bazel,cushon/bazel,bazelbuild/bazel,bazelbuild/bazel,twitter-forks/bazel,safarmer/bazel,dslomov/bazel,meteorcloudy/bazel,cushon/bazel,twitter-forks/bazel,dropbox/bazel,akira-baruah/bazel,werkt/bazel,ulfjack/bazel,aehlig/bazel,meteorcloudy/bazel,dropbox/bazel,dropbox/bazel,ButterflyNetwork/bazel,katre/bazel,dslomov/bazel,dropbox/bazel,ButterflyNetwork/bazel,werkt/bazel,aehlig/bazel,ulfjack/bazel,bazelbuild/bazel,dslomov/bazel-windows,perezd/bazel,dslomov/bazel,safarmer/bazel