This issue is really about modifying the editor template on Val Town:
strict: true is the TypeScript default and Deno doesn't override it, so should we do the same? Virtually all projects I encounter and work on use strict: true. I've swapped false for true for this setting for now, but should know if there was a footgun here that I'm not aware of. 
- Should we create 
deno.jsonc by default, so that it can have comments? This seems like an upgrade from deno.json and we need to support it anyway so should we default to it? 
/cc @404Wolf