Guidelines edit for prevent-log.txt

Title: Concept: Log
Section: Preventing and Fixing Problems
File name: prevent-log.txt
Covers: Explain that the site puts messages in the log when things happen and when things go wrong, and that it can be found in the Reports section.

Attribution

See https://userguide-drupal.redesign.devdrupal.org/guidelines/guidelines.ht...

Current attribution:

Adapted by https://www.drupal.org/u/diana.lakatos[Diána Lakatos] 
from https://www.drupal.org/getting-started/admin/reports["Reports"]
copyright 2000-2015 by the individual contributors to the
https://www.drupal.org/documentation[Drupal Community Documentation]

If you edit this topic, add your name to the attributions please.

Checklist for this phase

- Does it follow the template?
- Does it follow our guidelines on writing good documentation?
https://userguide-drupal.redesign.devdrupal.org/guidelines/good-writing....
- Does it follow the scenario?
- Does it speak to the intended audience?
- Does it have appropriate index entries?
- Is the navigation described in the standard way?
https://userguide-drupal.redesign.devdrupal.org/guidelines/text-conventi...