Current documentation is quite incomplete and not really sufficient to
write up a tour without looking at existing examples.
Try to better document the various options, and the relation between
`trigger`, `extra_trigger` (underscore, not dash), and `run`.
Also add the missing `content` and `timeout` step attributes.
closesodoo/documentation#2550
Related: odoo/odoo#96517
Related: odoo/enterprise#29824
Signed-off-by: Xavier Morel (xmo) <xmo@odoo.com>
