eol: be explicit about how to enable hook (issue2661)

hgext/eol.py

@@ -76,6 +76,8 b' The ``win32text.forbid*`` hooks provided'
 have been unified into a single hook named ``eol.hook``. The hook will
 lookup the expected line endings from the ``.hgeol`` file, which means
 you must migrate to a ``.hgeol`` file first before using the hook.
+Remember to enable the eol extension in the repository where you
+install the hook.
 
 See :hg:`help patterns` for more information about the glob patterns
 used.