[Request]: Template Strings for Preamble

[ericrallen]

Is your feature request related to a problem? Please describe.

When establishing a preamble, there are certain strings that would be helpful to be able to have templatized like today's date.

Describe the solution you'd like

A simple template syntax like %today% or {today} that runs the formatDate() utility and injects the current date into the preamble.