chore: Add development environment setup

[devin-ai-integration]

This PR adds the necessary development environment setup files and configurations to make it easier for developers to work on the project locally.

Changes include:

• Development environment configuration (.env.development)
• Development wrapper script (dev.sh)
• Test fixtures for local testing
• ShellCheck fixes in main.sh and utils.sh

Link to Devin run: https://preview.devin.ai/devin/1d9e099d3eab483c9a0a2ae493174bf2

If you have any feedback, you can leave comments in the PR and I'll address them in the app!

[github-actions]

Score: 85

Improvements:

• Use consistent naming conventions for shell scripts and variables to enhance readability and maintainability.
• Consider adding error handling in utils::parse_args for unknown arguments rather than just logging an error.
• Ensure that exported variables are explicitly defined as local within the function before exporting.
• Simplify and streamline the condition checking for required files and environment variables.

+utils::parse_args() {
+  # Use local variables within the function scope
+  local arg
+  # Iterate over provided arguments
+  for arg in "$@"; do
+    case "$arg" in
+      --github_token=*)
+        github_token="${arg#*=}"
+        export github_token
+        ;;
+      --open_ai_api_key=*)
+        open_ai_api_key="${arg#*=}"
+        export open_ai_api_key
+        ;;
+      --gpt_model_name=*)
+        gpt_model_name="${arg#*=}"
+        export gpt_model_name
+        ;;
+      --github_api_url=*)
+        github_api_url="${arg#*=}"
+        export github_api_url
+        ;;
+      --files_to_ignore=*)
+        files_to_ignore="${arg#*=}"
+        export files_to_ignore
+        ;;
+      *)
+        utils::log_error "Unknown argument: $arg"
+        exit 1
+        ;;
+    esac
+  done
+}