docs: clarify that driver manager is probably not what you want

Fixes apache#1981.

docs/source/python/driver_manager.rst

@@ -43,23 +43,34 @@ Installation
 Usage
 =====
 
-First create a :py:class:`AdbcDatabase`, passing ``driver`` and
-(optionally) ``entrypoint``. ``driver`` must be the name of a library
-to load, or the path to a library to load. ``entrypoint``, if
-provided, should be the name of the symbol that serves as the ADBC
+.. warning:: This API is for low level usage only. **You almost certainly
+ should not use this**, instead use the entrypoints provided by
+ driver packages, for example:
+
+ - :func:`adbc_driver_sqlite.dbapi.connect`
+ - :func:`adbc_driver_sqlite.connect`
+
+The Python bindings for each driver abstract the steps here for you behind a
+convenient ``connect`` function. For example, prefer
+:func:`adbc_driver_sqlite.connect` or :func:`adbc_driver_postgresql.connect`
+to manually constructing the connection as demonstrated here.
+
+To manually create a connection: first, create a :py:class:`AdbcDatabase`,
+passing ``driver`` and (optionally) ``entrypoint``. ``driver`` must be the
+name of a library to load, or the path to a library to load. ``entrypoint``,
+if provided, should be the name of the symbol that serves as the ADBC
 entrypoint (see :cpp:type:`AdbcDriverInitFunc`). Then, create a
 :py:class:`AdbcConnection`.
 
 .. code-block:: python
 
  import adbc_driver_manager
- with adbc_driver_manager.AdbcDatabase(driver="adbc_driver_sqlite") as db:
+
+ # You must build/locate the driver yourself
+ with adbc_driver_manager.AdbcDatabase(driver="PATH/TO/libadbc_driver_sqlite.so") as db:
  with adbc_driver_manager.AdbcConnection(db) as conn:
  pass
 
-The Python bindings for each driver abstract these steps for you
-behind a convenient ``connect`` function.
-
 API Reference
 =============