Change: Fix documentation regarding methods type promise outcomes

Ref: https://dev.cfengine.com/issues/6538
(cherry picked from commit 1b88ab725649c8fa60f436439ecdada41d8d1b31)
Updated example code to use slist

Updated example code to use slist instead of using a string.
(cherry picked from commit 7f68a6959cec9635e92bb1dee0c366161e965c17)
Document that now() returns agent start time

See redmine 4710 for discussion.
(cherry picked from commit 737b21898388773b91a9f0440aaceea1157c7708)