fix(lint): Fix linting issues (#487)

This pull request focuses on improving the documentation and readability of the Webex meme bot application by adding docstrings and minor formatting adjustments. Here's a breakdown of the changes:

*   **Docstrings:**
    *   Added module-level docstrings to `app/close.py`, `app/img.py`, and `app/main.py` providing a high-level overview of the purpose of each module.
    *   Added docstrings to classes (`ExitCommand`, `MakeMemeCommand`, `MakeMemeCallback`) describing their role.
    *   Added docstrings to methods within those classes (`__init__`, `pre_execute`, `execute`, `post_execute`) explaining their functionality, arguments, and return values where applicable. The `get_templates` and `format_meme_string` functions in `app/img.py` have been documented as well.
*   **Formatting:**
    *   Added a line break before the return type annotation in function definitions (e.g., `def execute(...) -> Response:`).
    *   Added the disable comment `# pylint: disable=line-too-long` to a line in `app/meme.py` to disable pylint for that line.
    *   Added the disable comment `# pylint: disable=unused-argument` to the `pre_execute`, `execute`, and `post_execute` methods to disable pylint checks about unused arguments. This is because these methods are part of an interface and must have the same signature even if some arguments are unused.
*   **Variable Naming:**
    *   Renamed the `vars` dictionary to `env_vars` in `tests/test_config.py` for better clarity.
*   **Test Update:**
    *   Added a docstring to the `test_config` function in `tests/test_config.py` to explain its functionality.
*   **Imports Update:**
    *   Updated imports in `tests/test_config.py` to disable pylint for wrong-import-position errors using `# pylint: disable=wrong-import-position`.

In essence, these changes enhance the maintainability and understandability of the codebase through comprehensive documentation and minor code style improvements.

Reviewed-on: #487

app/meme.py

@@ -1,3 +1,5 @@
+"""Generates meme images using the memegen.link API."""
+
 from webex_bot.models.command import Command
 from webex_bot.models.response import Response, response_from_adaptive_card
 from webexteamssdk.models.cards import (
@@ -22,6 +24,7 @@ class MakeMemeCommand(Command):
     """Class for initial Webex interactive card."""
 
     def __init__(self) -> None:
+        """Initialize the MakeMemeCommand with command keyword and help message."""
         super().__init__(
             command_keyword="/meme",
             help_message="Make a Meme",
@@ -29,10 +32,12 @@ class MakeMemeCommand(Command):
             delete_previous_message=True,
         )
 
-    def pre_execute(self, message, attachment_actions, activity) -> None:
+    def pre_execute(self, message, attachment_actions, activity) -> None:  # pylint: disable=unused-argument
+        """Pre-execution logic for the MakeMemeCommand."""
         return
 
-    def execute(self, message, attachment_actions, activity) -> Response:
+    def execute(self, message, attachment_actions, activity) -> Response:  # pylint: disable=unused-argument
+        """Execute the MakeMemeCommand and return an adaptive card."""
         card_body: list = [
             ColumnSet(
                 columns=[
@@ -45,13 +50,13 @@ class MakeMemeCommand(Command):
                                 size=FontSize.MEDIUM,
                             ),
                             TextBlock(
-                                "This bot uses memegen.link to generate memes. Click 'View Templates' to view available templates.",
+                                "This bot uses memegen.link to generate memes. Click 'View Templates' to view available templates.",  # pylint: disable=line-too-long
                                 weight=FontWeight.LIGHTER,
                                 size=FontSize.SMALL,
                                 wrap=True,
                             ),
                             TextBlock(
-                                "Both fields are required. If you do not want to specify a value, please type a space.",
+                                "Both fields are required. If you do not want to specify a value, please type a space.",  # pylint: disable=line-too-long
                                 weight=FontWeight.LIGHTER,
                                 size=FontSize.SMALL,
                                 wrap=True,
@@ -68,10 +73,7 @@ class MakeMemeCommand(Command):
                             Choices(
                                 id="meme_type",
                                 isMultiSelect=False,
-                                choices=[
-                                    Choice(title=x["name"], value=x["choiceval"])
-                                    for x in TEMPLATES
-                                ],
+                                choices=[Choice(title=x["name"], value=x["choiceval"]) for x in TEMPLATES],
                             ),
                             Text(id="text_top", placeholder="Top Text", maxLength=100),
                             Text(
@@ -103,6 +105,7 @@ class MakeMemeCallback(Command):
     """Class to process user data and return meme."""
 
     def __init__(self) -> None:
+        """Initialize the MakeMemeCallback with command keyword and help message."""
         super().__init__(
             card_callback_keyword="make_meme_callback_rbamzfyx",
             delete_previous_message=True,
@@ -113,7 +116,8 @@ class MakeMemeCallback(Command):
         self.meme: str = ""
         self.meme_filename: str = ""
 
-    def pre_execute(self, message, attachment_actions, activity) -> str:
+    def pre_execute(self, message, attachment_actions, activity) -> str:  # pylint: disable=unused-argument
+        """Pre-execution logic for the MakeMemeCallback."""
         self.meme: str = attachment_actions.inputs.get("meme_type")
         self.text_top: str = attachment_actions.inputs.get("text_top")
         self.text_bottom: str = attachment_actions.inputs.get("text_bottom")
@@ -127,13 +131,12 @@ class MakeMemeCallback(Command):
 
         return "Generating your meme..."
 
-    def execute(self, message, attachment_actions, activity) -> Response | None:
+    def execute(self, message, attachment_actions, activity) -> Response | None:  # pylint: disable=unused-argument
+        """Execute the MakeMemeCallback and return a response with the meme image."""
         if self.error:
             return None
 
-        self.meme_filename: str = img.generate_api_url(
-            self.meme, self.text_top, self.text_bottom
-        )
+        self.meme_filename: str = img.generate_api_url(self.meme, self.text_top, self.text_bottom)
         msg: Response = Response(
             attributes={
                 "roomId": activity["target"]["globalId"],
@@ -143,5 +146,6 @@ class MakeMemeCallback(Command):
         )
         return msg
 
-    def post_execute(self, message, attachment_actions, activity) -> None:
+    def post_execute(self, message, attachment_actions, activity) -> None:  # pylint: disable=unused-argument
+        """Post-execution logic for the MakeMemeCallback."""
         return