add doc-only substrate entry point crate (#14581)

* add doc-only substrate entry point crate

* document a few more things

* add more

* fix width

* Update primitives/io/src/lib.rs

Co-authored-by: Gonçalo Pestana <g6pestana@gmail.com>

* add link

* update cargo toml file

* fix sp-io docs

* improve

* small update

* add license

* satisfy license job

* add a line about FRAME

* CI happy now

* make CI more happy

* Let the check run for the whole workspace

* Forward the substrate node again as default run

* update binary names

* upate verison test

* Fix fix fix

* Fix

* rename to substrate-node in more places

* Revert "rename to substrate-node in more places"

This reverts commit 66960f84a1b6f1f7c638b4040e28e9fbabb8adf5.

* fix

* Fix build pipeline

* Fix properly plus add some docs

---------

Co-authored-by: Gonçalo Pestana <g6pestana@gmail.com>
Co-authored-by: Bastian Köcher <info@kchr.de>

substrate/client/cli/src/commands/mod.rs

@@ -15,6 +15,9 @@
 
 // You should have received a copy of the GNU General Public License
 // along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+//! Various subcommands that can be included in a substrate-based chain's CLI.
+
 mod build_spec_cmd;
 mod chain_info_cmd;
 mod check_block_cmd;