Standard updoc prelude for swt

From Erights

The following line

? pragma.syntax("0.9")

declares to updoc that further updoc passages on this page are in E 0.9 syntax.

The inner expression on following line

? interp.waitAtTop(currentVat.morphInto("swt"))

asks the current vat to become a vat executing within the SWT event loop. It returns a promise which will resolve once the request is either completed or refused.

The "interp.waitAtTop/1" pauses the command-line interpreter until its argument promise resolves. Assuming it's successful, further updoc passages on this page can now use SWT.