deno add fails to add a jsr: package to a deno.json when project only contains package.json

[DanieliusDev]

Version: Deno 2.0.0

How to reproduce

files:
package.json created manually
deno.json not created manually

$ deno add jsr:@std/assert
Add jsr:@std/[email protected]
error: npm package '@jsr/std__assert' does not exist.

what deno creates in package.json from running the above command

{
  "dependencies": {
    "@std/assert": "npm:@jsr/std__assert@^1.0.6"
  }
}

[tchajed]

I ran into this bug from following the instructions in the Vue tutorial (https://docs.deno.com/runtime/tutorials/how_to_with_npm/vue/). It might make sense to update the tutorial text or the npm:create-vite task if the fix to deno add will take longer.