File name should be able to be changed by the user with template variables

[Disane87]

Currently the filename is fixed. This should be changed toi enable the user to set the filename by his needs.

[Disane87]

We don't need any template library, we can achieve this by typescript only:

let stringWithVars = (str, obj) => str.replace(/\${(.*?)}/g, (x,g)=> obj[g]);

But this only applies when there is no computation or advanced formatting needed. Everything else needs a template engine like Handlebars or somethign else.

What do you think @fwartner?