fix: problem without readline module

Poor handling of inputs such as cursor movements using left and right
arrow keys. See more detail at issue #12 below:
#12

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "chatgpt-cli-md"
-version = "0.1.7"
+version = "0.1.8"
 description = "A markdown-supported command-line interface tool that connects to ChatGPT using OpenAI's API key."
 readme = { file = "README.md", content-type = "text/markdown" }
 requires-python = ">=3.8"

src/utils/io.py

@@ -1,6 +1,7 @@
 import os
 import sys
 import tempfile
+import readline
 import subprocess
 from typing import Dict
 
@@ -119,6 +120,7 @@ def user_input(prompt="\nUser: ") -> str:
         lines.append(line)
         # Update the prompt using readline
         prompt = "\r" + " " * len(prompt) + "\r" + " .... "
+        readline.get_line_buffer()
     # Print a message indicating that the input has been submitted
     msg = "\n\n".join(lines).strip()
     if not msg: