Create new post with `wyam` tool

[johanvergeer]

@daveaglick said in issue #843 that the timestamp can also be added to the filename.

Could it be possible to use the wyam tool to create a new post, where the date is already prepended to the file name and some basic frontmatter is already added.

You could even add some configuration in config.wyam to tell the tool whether the date should be added in the filename, frontmatter or don't include it at all, if you wish to use the functionality proposed in #843 .

[daveaglick]

I’d love to get something like this in the box, most other generators have a similar concept. There’s an open issue at https://github.com/Wyamio/Wyam/issues/696. I’m looking closely at it for v3 or shortly after. There’s a bunch of stuff I’d like to enhance in the CLI experience.

This is mostly a dup of #696 but I’ll leave it open since it’s got a little more detail about dealing with dates in the archetype.