We should move [effects documentation] over to the wiki.
...
I disagree, for the simple reason that there can never be such a thing
as THE effects documentation: the documentation depends on the version
of code used, and the (development version of the) code changes all the
time. I think that the documentation SHOULD be updated whenever there is
a change to the effects code; the version in SVN should never be allowed
to become out of date.
This is a good point. However, experience shows that documentation
included in the repository _does_ get out of sync with the code, fast,
despite many attempts to encourage people to update it. On the other hand,
documentation in the wiki gets updated much more quickly.
The reason is of course that there is a higher expectation of quality and
completeness when something is changed in the repository, which means the
bar for doing a change there is higher.