Make config clearer in log-strategies.md

[cap10morgan]

This wasn't working for me because nothing in here says it all needs to be the value of a :log-to key in the container config map. Reading the code and adding that made it work. Figured it might be nice to clarify that for others too.

[cap10morgan]

I see that the README does point out the top-level :log-to key, so let me know if there's a better way to clarify this. I do think it's helpful to point it out in some form in this file too.

[javahippie]

Hey @cap10morgan, thanks for the suggestion and the change! I also think that your change makes the documentation much cleaner.