Add command line options for setting log level and file

Two command line options are added for setting the Felis log level and,
optionally, an output file for log messages.

python/felis/cli.py

@@ -45,12 +45,30 @@
 
 logger = logging.getLogger("felis")
 
+loglevel_choices = ["CRITICAL", "FATAL", "ERROR", "WARNING", "INFO", "DEBUG"]
+
 
 @click.group()
 @click.version_option(__version__)
-def cli() -> None:
+@click.option(
+    "--loglevel",
+    type=click.Choice(loglevel_choices),
+    envvar="FELIS_LOGLEVEL",
+    help="Felis log level",
+    default=logging.getLevelName(logging.INFO),
+)
+@click.option(
+    "--logfile",
+    type=click.Path(),
+    envvar="FELIS_LOGFILE",
+    help="Felis log file path",
+)
+def cli(loglevel: str, logfile: str | None) -> None:
     """Felis Command Line Tools."""
-    logging.basicConfig(level=logging.INFO)
+    if logfile:
+        logging.basicConfig(filename=logfile, level=loglevel)
+    else:
+        logging.basicConfig(level=loglevel)
 
 
 @cli.command("create-all")