Add custom vocab instructions to USE (#294)

Co-authored-by: Jen Person <[email protected]>
Co-authored-by: Matthew Soulanille <[email protected]>

Author: 3 people

universal-sentence-encoder/README.md

@@ -83,6 +83,15 @@ use.loadTokenizer().then(tokenizer => {
 });
 ```
 
+
+Pass a path to the Tokenizer to use a different vocabulary:
+
+```js
+use.loadTokenizer('https://storage.googleapis.com/learnjs-data/bert_vocab/vocab.json').then(tokenizer => {
+  tokenizer.encode('Hello, how are you?'); // [0, 15350, 29623, 2129, 2024, 2017, 29632]
+});
+```
+
 To use the QnA dual encoder:
 ```js
 // Load the model.