[Word] Feature Request: Support for Range Start and End properties similar to C# Word Interop

I’d like to request a feature for the Word API: **exposing `start` and `end` properties on the `Range` object**, similar to what is available in C# Word Interop.

In C#, a `Range` object has `Start` and `End` properties that allow precise control over range manipulation, comparisons, and modifications. For example, this enables developers to:

- Insert content at a specific location
- Expand or shrink a range programmatically

Currently in Office-JS, the `Range` object abstracts away the positional information, making some of these scenarios much harder or impossible to implement.

#### Feature suggestion
Introduce something like:
```js
range.start; // Returns the position index from the beginning of the document
range.end;   // Returns the end index
```

#### Example use cases
- Insert content at a specific location
- Navigating document content by position

This would significantly improve the capabilities for building more sophisticated Word add-ins.

Thanks for considering this feature!