Steamers are akin to that of Telescope's Pickers. A "steamer" is the
class structure used by builtins to create new windows/buffers for the
user to interact with. This code was simply migrated across from
presser@new and refactored to adopt a class-like OOP paradigm.
steamers@new is a wrapper function accessed by builtins to invoke the
class constructor Steamers@new. Allows to greater control and
flexibility of window/buffer options.
