install with Deno 2 runtime

[adunne09]

https://jsr.io/@extism/extism and import createPlugin from "jsr:@extism/extism"; here in the README indicate that there is an extism jsr package, but when I run deno add jsr:@extism/extism, I get:

error: jsr:@extism/extism was not found, but a matching npm package exists. Did you mean `deno add npm:@extism/extism`

Is this the intended behavior, or is there meant to be an extism jsr package?