doc: remove the section about share-safe from its verbose gating

The feature is no longer experimental.

Differential Revision: https://phab.mercurial-scm.org/D9838

mercurial/helptext/config.txt

@@ -147,8 +147,6 b' be overridden in other configuration fil'
 merge tool configuration but packagers can also put other default configuration
 there.
 
-.. container:: verbose
-
     On versions 5.7 and later, if share-safe functionality is enabled,
     shares will read config file of share source too.
     `<share-source/.hg/hgrc>` is read before reading `<repo/.hg/hgrc>`.