Introduces a new `config` module for loading application settings from
environment variables and a `users.toml` file. An `error` module is
added to handle application-specific errors gracefully. An
`.env.example` file is created to show available configuration options,
and `users.toml.example` provides a template for user data. The main
function now initializes the configuration and prints the server port.
This commit introduces a .gitignore file to exclude build artifacts and
temporary files from version control.
Specifically, it ignores the 'target' directory (where Rust builds
output), new snapshot files from tests (`*.snap.new`), and the
`repomix-output.xml` file.
Brummel