docs: add vectorstore docs (#22)

* docs: add vectorstore docs * Update docs/vector_store.ipynb Co-authored-by: Jack Wotherspoon <jackwoth@google.com> * Update docs/vector_store.ipynb Co-authored-by: Jack Wotherspoon <jackwoth@google.com> * Update docs/vector_store.ipynb Co-authored-by: Jack Wotherspoon <jackwoth@google.com> * Update docs/vector_store.ipynb Co-authored-by: Jack Wotherspoon <jackwoth@google.com> * update * Update * Update docs/vector_store.ipynb Co-authored-by: Jack Wotherspoon <jackwoth@google.com> * Update docs/vector_store.ipynb Co-authored-by: Jack Wotherspoon <jackwoth@google.com> * update * rename --------- Co-authored-by: Jack Wotherspoon <jackwoth@google.com>

Author: averikitsch