I downloaded the 64bit Windows installed for "Tor Browser" from this url

https://www.torproject.org/download/download-easy.html.en

It installed and worked as expected and can display normal and .onion sites.

The first default page it displays is  about:tor

Under "you can help" there is a link called "**Run a Tor Relay Node »**"
to 

https://www.torproject.org/docs/tor-doc-relay.html.en

which says

>Alas, since Vidalia (a graphical interface for Tor) is no longer included in Tor Browser, there are currently no easy relay packages for Windows and OS X users.

followed by "**Configure Tor by editing the torrc file**"

I edited my "....\Tor Browser\Browser\TorBrowser\Data\Tor\torrc" file as directed and added the port forward to my firewall.

Unfortunately the Tor Browser failed to start after that and entered a "failed to start, need to restart" loop.

I enabled debug logging but nothing was added to the log during these events.
I reverted the edits and verified the logging system actually worked.
I trawled the tor site, google and this site for further explicit information with no luck.

I am now assuming that the "Tor Browser" is 100% client and cannot relay traffic for any other users of the network. 

Am I correct ? and if not, how do I active the relay functionality.
Thanks.

**Clarification**

I understand and followed the instructions on the Tor site. What I don't know is if they failed because they were *never intended to work on the Tor Browser* or for some other reason.