split-string description in the ELR

[Jean-Christophe Helary]

Without Eli's comment I would never have thought of using split-string to trim 
a string. But even reading the reference did not make it's use super clear. In 
the description "trim" is just an option to trim the substrings resulting from 
splitting the string and it is not obvious that it can be used on it's own to 
trim a given string.

Could a small modification of the reference be in order to emphasize that use 
(with an example eventually) ?

Jean-Christophe