add info about where scripts need to be and about them needing to be executable files.
add info about where scripts need to be and about them needing
to be executable files.

TODO: speak with lm and beth to get clarifications on some other
info that needs to be added to this page.

bk: 3a5c17f7FwqyjtVWfPCidypjUnXuNw
bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper,bitkeeper-scm/bitkeeper