update README documentation for RO (#63)

* README: update documentation for RO support

update the README and the install_dependencies script to match the
requirements of the RO conduit.

* add CODEOWNERS file

[ROCm/rocshmem commit: 4e48c9748e]

projects/rocshmem/scripts/install_dependencies.sh

@@ -35,7 +35,6 @@ git checkout $_UCX_COMMIT_HASH
                             --without-go               \
                             --without-java             \
                             --without-cuda             \
-                            --without-verbs            \
                             --without-knem
 make -j
 make install
@@ -56,7 +55,6 @@ git submodule update --init --recursive
             --with-hwloc=internal        \
             --with-libevent=internal     \
             --without-cuda               \
-            --disable-sphinx             \
             --disable-mpi-fortran        \
             --without-ofi
 make -j