Resolves #622

Description

This PR introduces the initial setup for running xDEM via a command-line interface (CLI). The CLI allows users to pass two DEM files (a reference DEM and a DEM to be aligned) as arguments, and provides additional configuration options like log level and version display. Currently, the command outputs a simple "hello world" message, as the core functionality will be implemented in future iterations (#623).

Key Changes:

1. Added xdem_cli.py:

   • Implements the main CLI functionality.
   • Defines a get_parser() function using argparse to handle the following arguments:
     • reference_dem: Path to the reference DEM file.
     • dem_to_be_aligned: Path to the DEM that will be aligned.
     • --loglevel: Option to set the logging level (defaults to INFO).
     • --version or -v: Displays the version of xDEM.

2. Added run() Function in __init__.py:

   • This function currently prints "hello world" as a placeholder for the actual DEM comparison functionality that will be added later.
   • It accepts three arguments: reference_dem, dem_to_be_aligned, and verbose.

3. Setup CLI Entry Points in setup.cfg:

   • Configured the entry point for the xdem CLI command.
   • Running xdem <path_to_reference_dem> <path_to_dem_to_be_aligned> in the terminal will now trigger the CLI interface.

Testing:

A unit test test_cli.py has been added to verify that the CLI can be executed and that it produces the expected output.

Documentation

Updated the quickstart guide (doc/source/quickstart.md) to include a section on using the new CLI, including the available options and an example command.

Future Work:

• The current CLI implementation does not perform any actual DEM comparison. The next step will be to integrate coregistration functionality into the run() function, which will be handled in [POC] simple CLI nuth and kaab #623.
• More comprehensive tests and documentation will be added once the core functionality is implemented.