No CJK support?

Just tested with Chinese, blaze currently does not support it. Any plan on supporting custom tokenizer (e.g. Unicode code point tokenizer)? Thanks.

```go
package main

import (
"fmt"

"github.com/wizenheimer/blaze"
)

func main() {
// Create a new inverted index
idx := blaze.NewInvertedIndex()

// Index some documents
idx.Index(1, "你好，世界")

// Search with BM25 ranking
matches := idx.RankBM25("好", 10)

// Print results
for _, match := range matches {
fmt.Printf("Document %d (score: %.2f)\n", match.DocID, match.Score)
}
}
```

The issue demonstrates that Chinese text is not tokenized correctly. Examine the tokenizer in the blaze codebase, likely in a file like tokenizer.go. Research Unicode segmentation and how to integrate a custom tokenizer. A solution may involve modifying the tokenizer interface or adding a new tokenizer implementation. Testing will require verifying that Chinese characters are properly indexed and searched.

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