Documentation: Strip idiomatic REPL prompt from landing page examples

Replicating the REPL prompt is nice and all, and the `sphinx-copybutton`
addon will nicely filter it when copy/pasting the code snippet.

However, not all people have JavaScript enabled, and it will probably
also fall short on accessibility aspects, and nothing of this kind will
ever be found on other code examples, so let's remove it.

Author: amotl

docs/index.rst

@@ -58,34 +58,34 @@ Install package from PyPI.
 
 .. code-block:: shell
 
-    $ pip install crate
+    pip install crate
 
 Connect to CrateDB instance running on ``localhost``.
 
 .. code-block:: python
 
-    >>> # Connect using DB API.
-    >>> from pprint import pp
-    >>> from crate import client
-    >>>
-    >>> query = "SELECT country, mountain, coordinates, height FROM sys.summits ORDER BY country;"
-    >>>
-    >>> with client.connect("localhost:4200", username="crate") as connection:
-    ...     cursor = connection.cursor()
-    ...     cursor.execute(query)
-    ...     pp(cursor.fetchall())
-    ...     cursor.close()
+    # Connect using DB API.
+    from crate import client
+    from pprint import pp
+
+    query = "SELECT country, mountain, coordinates, height FROM sys.summits ORDER BY country;"
+    
+    with client.connect("localhost:4200", username="crate") as connection:
+        cursor = connection.cursor()
+        cursor.execute(query)
+        pp(cursor.fetchall())
+        cursor.close()
 
 Connect to `CrateDB Cloud`_.
 
 .. code-block:: python
 
-    >>> # Connect using DB API.
-    >>> from crate import client
-    >>> connection = client.connect(
-    ...     servers="https://example.aks1.westeurope.azure.cratedb.net:4200",
-    ...     username="admin",
-    ...     password="<PASSWORD>")
+    # Connect using DB API.
+    from crate import client
+    connection = client.connect(
+        servers="https://example.aks1.westeurope.azure.cratedb.net:4200",
+        username="admin",
+        password="<PASSWORD>")
 
 
 SQLAlchemy
@@ -104,49 +104,49 @@ Install package from PyPI with DB API and SQLAlchemy support.
 
 .. code-block:: shell
 
-    $ pip install 'crate[sqlalchemy]' pandas
+    pip install 'crate[sqlalchemy]' pandas
 
 Connect to CrateDB instance running on ``localhost``.
 
 .. code-block:: python
 
-    >>> # Connect using SQLAlchemy Core.
-    >>> from pprint import pp
-    >>> import sqlalchemy as sa
-    >>>
-    >>> dburi = "crate://localhost:4200"
-    >>> query = "SELECT country, mountain, coordinates, height FROM sys.summits ORDER BY country;"
-    >>>
-    >>> engine = sa.create_engine(dburi, echo=True)
-    >>> with engine.connect() as connection:
-    ...     with connection.execute(sa.text(query)) as result:
-    ...         pp(result.mappings().fetchall())
+    # Connect using SQLAlchemy Core.
+    import sqlalchemy as sa
+    from pprint import pp
+    
+    dburi = "crate://localhost:4200"
+    query = "SELECT country, mountain, coordinates, height FROM sys.summits ORDER BY country;"
+    
+    engine = sa.create_engine(dburi, echo=True)
+    with engine.connect() as connection:
+        with connection.execute(sa.text(query)) as result:
+            pp(result.mappings().fetchall())
 
 Connect to `CrateDB Cloud`_.
 
 .. code-block:: python
 
-    >>> # Connect using SQLAlchemy Core.
-    >>> import sqlalchemy as sa
-    >>> dburi = "crate://admin:<PASSWORD>@example.aks1.westeurope.azure.cratedb.net:4200?ssl=true"
-    >>> engine = sa.create_engine(dburi, echo=True)
+    # Connect using SQLAlchemy Core.
+    import sqlalchemy as sa
+    dburi = "crate://admin:<PASSWORD>@example.aks1.westeurope.azure.cratedb.net:4200?ssl=true"
+    engine = sa.create_engine(dburi, echo=True)
 
 Load results into `pandas`_ DataFrame.
 
 .. code-block:: python
 
-    >>> # Connect using SQLAlchemy Core and pandas.
-    >>> import pandas as pd
-    >>> import sqlalchemy as sa
-    >>>
-    >>> dburi = "crate://localhost:4200"
-    >>> query = "SELECT * FROM sys.summits ORDER BY country;"
-    >>>
-    >>> engine = sa.create_engine(dburi, echo=True)
-    >>> with engine.connect() as connection:
-    ...     df = pd.read_sql(sql=sa.text(query), con=connection)
-    ...     df.info()
-    ...     print(df)
+    # Connect using SQLAlchemy Core and pandas.
+    import pandas as pd
+    import sqlalchemy as sa
+    
+    dburi = "crate://localhost:4200"
+    query = "SELECT * FROM sys.summits ORDER BY country;"
+    
+    engine = sa.create_engine(dburi, echo=True)
+    with engine.connect() as connection:
+        df = pd.read_sql(sql=sa.text(query), con=connection)
+        df.info()
+        print(df)
 
 
 Data types