alloy(role): add documentation

- add README
- add argument_specs
- removed tags

roles/alloy/tasks/install_debian.yml

@@ -1,20 +0,0 @@
----
-- name: Add grafana apt repo with signing key
-  become: true
-  ansible.builtin.deb822_repository:
-    name: grafana
-    types: deb
-    uris: https://apt.grafana.com
-    suites: stable
-    components:
-      - main
-    signed_by: https://apt.grafana.com/gpg.key
-
-- name: Run cache update
-  ansible.builtin.apt:
-    update_cache: true
-
-- name: Install alloy
-  become: true
-  ansible.builtin.package:
-    name: alloy