docs(cli): clarify checkupdates behavior

Add help text for --use-checkupdates and clarify that checkupdates is
provided by pacman-contrib and checks for available updates without
modifying the system package databases.

Separate the AUR update documentation into its own paragraph for
readability.

1 files changed, 10 insertions, 3 deletions

diff --git a/prometheus_pacman_exporter/__init__.py b/prometheus_pacman_exporter/__init__.py
index ac76dc6..cb19032 100644
--- a/prometheus_pacman_exporter/__init__.py
+++ b/prometheus_pacman_exporter/__init__.py
@@ -123,7 +123,11 @@ def run_command(
     help="Directory where the Prometheus collector textfile will be written.",
 )
 @click.option(
-    "--use-checkupdates", "use_checkupdates_flag", is_flag=True, default=False
+    "--use-checkupdates",
+    "use_checkupdates_flag",
+    is_flag=True,
+    default=False,
+    help="Use checkupdates to check for package updates.",
 )
 @click.option(
     "--aur", "aur_flag", is_flag=True, default=False, help="Include AUR updates."
@@ -177,8 +181,11 @@ def prometheus_pacman_exporter(
 
     By default, updateable packages are determined using ``pacman --query
     --upgrades``. Use ``--use-checkupdates`` to query updates with
-    ``checkupdates`` instead. AUR update metrics can optionally be collected by
-    providing ``--aur`` together with ``--aur-command``.
+    ``checkupdates`` from ``pacman-contrib`` instead, without modifying the
+    system package databases.
+
+    AUR update metrics can optionally be collected by providing ``--aur``
+    together with ``--aur-command``.
     """
 
     ctx.ensure_object(dict)