Update cpp-use-cases.md
Update cpp-use-cases.md

I wasn't able to build a simple 'hello-world' example with an identical structure.  I encountered several problems:
1) bazel forces to declare a license for code within the 'third_party' sub-directory.  This not at all obvious to noobs.
2) bazel complains about a missing input file 'some_lib.h' without the leading 'include' in hdrs and the build fails.
3) compilation throws "No such file or directory" when trying to include 'some_lib.h' with the trailing 'include' in copts.

I think this is particularly important for converting legacy projects (not necessarily third party) that use cmake, autoconf, etc...

Closes #4697.

PiperOrigin-RevId: 188471650

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