Proposal. Simplify point 4.5 (Filter)

In this part of best practice I found a part of code
```
// bad
inbox.filter((msg) => {
const { subject, author } = msg;
if (subject === 'Mockingbird') {
return author === 'Harper Lee';
} else {
return false;
}
});

// good
inbox.filter((msg) => {
const { subject, author } = msg;
if (subject === 'Mockingbird') {
return author === 'Harper Lee';
}

return false;
});
```

But, it seems that we can write this part of code better:

```
inbox.filter((msg) => {
const { subject, author } = msg;
return subject === 'Mockingbird' && author === 'Harper Lee';
});
```
Isn't it?

Thanks,
Andrii

Start with point 4.5 (Filter) in the best-practice documentation and compare the existing “bad” and “good” examples with the proposed expression. Done means updating the example if the shorter filter is accepted and preserving the section’s intended guidance.

Written by the indexing model from the issue text.