Update Transformers.js example code (#4)

- Update Transformers.js example code (ccf756833ba555e29e9b5b48288c2bf061ec8fda)


Co-authored-by: Joshua <[email protected]>

README.md

@@ -2733,14 +2733,20 @@ The model natively supports scaling of the sequence length past 2048 tokens. To
 import { pipeline } from '@xenova/transformers';
 
 // Create a feature extraction pipeline
-const extractor = await pipeline('feature-extraction', 'nomic-ai/nomic-embed-text-v1', {
+const extractor = await pipeline('feature-extraction', 'nomic-ai/nomic-embed-text-v1.5', {
     quantized: false, // Comment out this line to use the quantized version
 });
 
+// Define sentences
+const texts = ['search_query: What is TSNE?', 'search_query: Who is Laurens van der Maaten?'];
+
 // Compute sentence embeddings
-const texts = ['What is TSNE?', 'Who is Laurens van der Maaten?'];
-const embeddings = await extractor(texts, { pooling: 'mean', normalize: true });
-console.log(embeddings);
+let embeddings = await extractor(texts, { pooling: 'mean' });
+console.log(embeddings); // Tensor of shape [2, 768]
+
+const matryoshka_dim = 512;
+embeddings = embeddings.slice(null, [0, matryoshka_dim]).normalize(2, -1);
+console.log(embeddings); // Tensor of shape [2, 512]
 ```
 
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