Explain in Troubleshooting.md why "const anyModule = module as any;" doesn't work as expected

At https://github.com/gaearon/react-hot-loader/blob/master/docs/Troubleshooting.md, you say that

```
const anyModule = module as any;
if (anyModule.hot) {
anyModule.hot.accept('./app', () => render(App));
}
```

will lead to full page reloads, but

```
if ((module as any).hot) {
(module as any).hot.accept('./app', () => render(App));
}
```

will work. I am pretty confused by that, as I'd expect both to lead to the same result. Not understanding it makes it harder to remember too.

Could you maybe add to the document why it is behaving like this?

(Or if you don't have the time to do that at the moment, give me a hint here?)

Open docs/Troubleshooting.md and read the section containing the two module.hot examples. Compare the behavior described for the assigned variable and the inline type assertion, then document why they differ. Done means the troubleshooting guidance explains the distinction clearly enough that readers can understand and remember it.

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