Update get_certificate.py (#56594)

* Update get_certificate.py with an example to calculate number of days until cert expires from get_certificate result.

* Update lib/ansible/modules/crypto/get_certificate.py

Co-Authored-By: Felix Fontein <felix@fontein.de>

lib/ansible/modules/crypto/get_certificate.py

@@ -107,6 +107,12 @@ EXAMPLES = '''
   delegate_to: localhost
   run_once: true
   register: cert
+
+- name: How many days until cert expires
+  debug:
+    msg: "cert expires in: {{ expire_days }} days."
+  vars:
+    expire_days: "{{ (( cert.not_after | to_datetime('%Y%m%d%H%M%SZ')) - (ansible_date_time.iso8601 | to_datetime('%Y-%m-%dT%H:%M:%SZ')) ).days }}"
 '''
 
 import traceback