Minor documentation feedbacks

[Guillaume Labourey]

On the documentation, there is some ambiguous description or mistake in the following files:

• warming_up.qbk, line 105: According to the code sample, "last" iterator may be more appropriate than "str.end()"

• what_s_new.qbk, line 116: There is a mismatch between struct name and constructor name. "example_lexer()" should be replaced by "example_tokens()"

Regards, Guillaume

[anonymous]

Fixed. Thanks!