Template: Add ability to use macros like %date% to insert todays date

[mvandenbos]

It would be great to have the ability to use a %Date% macro in the template text entered by the user to allow for entering today's date.

[koehdaniel]

Should not be todays Date, but the Date specified in the Template-Config templateData.letter.signature.date

[koehdaniel]

Maybe best way for a generic approach is to give the user the ability to add his own variables at the top of the Template Editor.

Then he can for example create a custom variable with the key "myDate" and the value "23.11.2019" and use it inside any text block and also inside templateData.letter.signature.date if he wants by typing %myDate%