docs: add project ID to pandas-gbq run sample (#17692)

Fixes #<522958409> 🦕

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Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: shuoweil

packages/pandas-gbq/README.rst

@@ -45,8 +45,15 @@ Perform a query
 
     import pandas_gbq
 
+    # If running in your local environment or Colab, use the code below and specify your GCP project ID
+    # result_dataframe = pandas_gbq.read_gbq("SELECT * FROM bigquery-public-data.usa_names.usa_1910_2013 LIMIT 10", project_id="your-project-id")
+
     result_dataframe = pandas_gbq.read_gbq("SELECT column FROM dataset.table WHERE value = 'something'")
 
+.. note::
+
+    A Google Cloud project ID can be quickly obtained as described `here <https://docs.cloud.google.com/bigquery/docs/sandbox>`_.
+
 Upload a dataframe
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