[docs] Remove reference to adding namespace to coordinator config (#2977)
[docs] Remove reference to adding namespace to coordinator config (#2977)

Co-authored-by: Chris Chinchilla <711c73f64afdce07b7e38039a96d2224209e9a6c@chronosphere.io>
m3db/m3db,m3db/m3db,m3db/m3db,m3db/m3db