Update README.adoc
Update README.adoc

Added the new `Live Preview Refresh Delay` parameter description, @Anthonny. 

NOTE: This is different to what it is currently called in the demo site. I would suggest changing the field description in the code to mirror the docs (I think it better reflects the purpose of the field).
demo-hubpress/demo-hubpress.github.io,alchapone/alchapone.github.io,lametaweb/lametaweb.github.io,TheAshwanik/new,lametaweb/lametaweb.github.io,anthonny/dev.hubpress.io,Git-Host/Git-Host.io,anthonny/dev.hubpress.io,demo-hubpress/demo-hubpress.github.io,anthonny/dev.hubpress.io,anthonny/dev.hubpress.io,demo-hubpress/demo-hubpress.github.io,TheAshwanik/new,demo-hubpress/demo-hubpress.github.io,lametaweb/lametaweb.github.io,TheAshwanik/new,alchapone/alchapone.github.io,Git-Host/Git-Host.io,demo-hubpress/demo-hubpress.github.io,TheAshwanik/new,Git-Host/Git-Host.io,anthonny/dev.hubpress.io,alchapone/alchapone.github.io