r/lego-nginx: Configure LEGO for nginx

The *lego-nginx* role automates obtaining certificates for *nginx* via
ACME using `lego`.  It generates a shell script with the appropriate
arguments for `lego run`, runs it once to obtain a certificate
initially, then schedules it to run periodically via a systemd timer
unit. Using `lego`'s "hook" capability, the script signals the `nginx`
server process to reload.  This uses `doas` for now, but could be
adapted easily to use `sudo`, if the need ever arises.

roles/lego-nginx/tasks/main.yml

@@ -0,0 +1,8 @@
+- import_tasks: nginx.yml
+  tags:
+  - nginx
+  - lego-nginx
+
+- import_tasks: cert.yml
+  tags:
+  - lego-nginx