Readonly create store if args is not unitable

Sometimes needed readonly store from incoming arguments outside, in factories functions for examle.
How can a solution be processed inside a function an argument that is not a unit by creating a unit from it

there is now:
```ts
const someFunction(arg1:number, arg2:string) {
const $store = readonly(createStore(arg1));
}
```

and how can it be:

```ts
const someFunction(arg1:number, arg2:string) {
const $store = readonly(arg1);
}
```

Start by reviewing the existing readonly and createStore APIs and how they handle arguments that are not units. The issue does not name a source file or test, so first locate the relevant operator implementation and tests. Done should mean a documented, tested way to create a readonly store directly from an incoming argument.

Written by the indexing model from the issue text.