bots: Migrate source file for zulip-bot-shell to similar name.

zulip_bots/README.md

@@ -21,6 +21,6 @@ zulip_bots  # This directory
 │   ├───simple_lib.py  # Used for terminal testing.
 │   ├───test_lib.py  # Backbone for bot unit tests.
 │   ├───test_run.py  # Unit tests for run.py
-│   └───terminal.py  # Used to test bots in the command line.
+│   └───bot_shell.py  # Used to test bots in the command line.
 └───setup.py  # Script for packaging.
 ```

zulip_bots/setup.py

@@ -52,7 +52,7 @@ package_info = dict(
     entry_points={
         "console_scripts": [
             "zulip-run-bot=zulip_bots.run:main",
-            "zulip-bot-shell=zulip_bots.terminal:main",
+            "zulip-bot-shell=zulip_bots.bot_shell:main",
         ],
     },
 )  # type: Dict[str, Any]