make it explicit about the vector column data type (#916)

<img width="837" alt="Screenshot 2024-02-01 at 4 23 34 PM"
src="https://github.com/lancedb/lancedb/assets/1305083/4f0f5c5a-2a24-4b00-aad1-ef80a593d964">
[
<img width="838" alt="Screenshot 2024-02-01 at 4 26 03 PM"
src="https://github.com/lancedb/lancedb/assets/1305083/ca073bc8-b518-4be3-811d-8a7184416f07">
](url)

---------

Co-authored-by: Weston Pace <weston.pace@gmail.com>

docs/src/guides/tables.md

@@ -84,7 +84,7 @@ This guide will show how to create tables, insert data into them, and update the
     const table = await con.createTable(tableName, data, { writeMode: WriteMode.Overwrite })
     ```
 
-### From a Pandas DataFrame
+    ### From a Pandas DataFrame
 
     ```python
     import pandas as pd
@@ -100,7 +100,9 @@ This guide will show how to create tables, insert data into them, and update the
     db["my_table"].head()
     ```
     !!! info "Note"
-        Data is converted to Arrow before being written to disk. For maximum control over how data is saved, either provide the PyArrow schema to convert to or else provide a PyArrow Table directly.
+    Data is converted to Arrow before being written to disk. For maximum control over how data is saved, either provide the PyArrow schema to convert to or else provide a PyArrow Table directly.
+
+    The **`vector`** column needs to be a [Vector](../python/pydantic.md#vector-field) (defined as [pyarrow.FixedSizeList](https://arrow.apache.org/docs/python/generated/pyarrow.list_.html)) type. 
 
     ```python
     custom_schema = pa.schema([

python/lancedb/table.py

@@ -438,6 +438,8 @@ class Table(ABC):
             the table
         vector_column_name: str
             The name of the vector column to search.
+
+            The vector column needs to be a pyarrow fixed size list type
             *default "vector"*
         query_type: str
             *default "auto"*.