minuscule typo in the documentation of s3sync function

[fBedecarrats]

The help documentation for the s3sync function reads:

prefix: string, if set to non-empty string, leading part of the objects in the bucket much have that prefix, other objects are not considered. In practice, this alows the immitation of sub-directories in the bucket and in that case it is typically required that the training slash is included in the prefix.

Where training should read trailing