Notebook to assist with bringing data from BigQuery to Sheets

[max-ostapenko]

There were quite a few discussions before on querying the data from the bigquery and uploading it to the Spreadsheets.

Here is the notebook I've been using. Looking forward to improve it according to the analysts workflow.

• [x] notebook added: sql/util/bq_to_sheets.ipynb
• [x] short description in utils readme

[max-ostapenko]

Will cover it also in analysts guide after merging.