Please explain your feature request to the best of your abilities:

For the command that lets you change the spawn location of an outpost plot/chunk:

/plot set outpost spawn

all params auto complete except for "spawn", not sure if there are other options other than "spawn" adding this would make it much more intuitive for players/admins, I have been around towny for many many years and I always thought that the only way to change an outpost's spawn point was to do /plot set outpost, which charges the town for the price of an entirely new outpost.

It could also be added to the wiki if it is not already.

So the commands are a bit outdated, and I might change things but currently this is how they work:

/t claim outpost claims a new plot and makes it an outpost.
/plot set outpost makes an already claimed plot into an outpost, it is a fairly recently-added command.
/t set outpost sets the spawnpoint of an already existing outpost. This aligns with /t set spawn and has been around a lot longer than /plot set outpost.