A `Help_text.t` represents the documentation for a collection of commands. It can be displayed as a Vdom node.

This can be used to create a web ui help menu.

`module View_spec : sig ... end`
`module Command : sig ... end`
`type t`````
`include sig ... end`
`val t_of_sexp : Base.Sexp.t ‑> t`
`val sexp_of_t : t ‑> Base.Sexp.t`
`val compare : t ‑> t ‑> int`
`val empty : t`
`val is_empty : t ‑> bool`
`val of_command_list : Command.t list ‑> t`
`val add_command : t ‑> Command.t ‑> t`

`add_command` is linear in the number of commands in `t`.

`val commands : t ‑> Command.t list`
`val view : ?⁠sep:string ‑> t ‑> View_spec.t ‑> Incr_dom_widgets__.Import.Vdom.Node.t`

`view` displays a help text table with one row per command.

`view_rows` is similar to `view`, but returns a list of row nodes instead of wrapping them in a table node.

`val view_rows : ?⁠sep:string ‑> t ‑> View_spec.t ‑> Incr_dom_widgets__.Import.Vdom.Node.t list`