Add more information about log files in User Guide

[exalate-issue-sync]

Add this extra info to the user guide: http://docs.h2o.ai/h2o/latest-stable/h2o-docs/logs.html

Describe why the files are separated into different pieces (.1, .2, .3):

Reason: its “age”, .log is the current log being written to, log.1 is the one before, log.2 is older still and so on, each time .log reaches certain size it is renamed to log.1 and the log.1 is renamed to log.2 and so on

{code:bash}
-rw-r--r-- 1 ledell ledell 0 Feb 2 09:42 h2o_127.0.0.1_16537-6-fatal.log
-rw-r--r-- 1 ledell ledell 0 Feb 2 09:42 h2o_127.0.0.1_16537-5-error.log
-rw-r--r-- 1 ledell ledell 3.1M Feb 2 10:23 h2o_127.0.0.1_16537-3-info.log.3
-rw-r--r-- 1 ledell ledell 3.1M Feb 2 10:23 h2o_127.0.0.1_16537-2-debug.log.3
-rw-r--r-- 1 ledell ledell 1.1M Feb 2 10:30 h2o_127.0.0.1_16537-httpd.log.3
-rw-r--r-- 1 ledell ledell 3.1M Feb 2 10:35 h2o_127.0.0.1_16537-3-info.log.2
-rw-r--r-- 1 ledell ledell 3.1M Feb 2 10:35 h2o_127.0.0.1_16537-2-debug.log.2
-rw-r--r-- 1 ledell ledell 1.1M Feb 2 10:41 h2o_127.0.0.1_16537-1-trace.log.3
-rw-r--r-- 1 ledell ledell 1.1M Feb 2 10:54 h2o_127.0.0.1_16537-httpd.log.2
-rw-r--r-- 1 ledell ledell 1.1M Feb 2 11:18 h2o_127.0.0.1_16537-1-trace.log.2
-rw-r--r-- 1 ledell ledell 1.1M Feb 2 11:50 h2o_127.0.0.1_16537-httpd.log.1
-rw-r--r-- 1 ledell ledell 3.1M Feb 2 12:33 h2o_127.0.0.1_16537-3-info.log.1
-rw-r--r-- 1 ledell ledell 3.1M Feb 2 12:33 h2o_127.0.0.1_16537-2-debug.log.1
-rw-r--r-- 1 ledell ledell 1.1M Feb 2 12:33 h2o_127.0.0.1_16537-1-trace.log.1
-rw-r--r-- 1 ledell ledell 903K Feb 2 12:39 h2o_127.0.0.1_16537-httpd.log
-rw-r--r-- 1 ledell ledell 39K Feb 2 12:39 h2o_127.0.0.1_16537-4-warn.log
-rw-r--r-- 1 ledell ledell 286K Feb 2 12:39 h2o_127.0.0.1_16537-3-info.log
-rw-r--r-- 1 ledell ledell 286K Feb 2 12:39 h2o_127.0.0.1_16537-2-debug.log
-rw-r--r-- 1 ledell ledell 285K Feb 2 12:39 h2o_127.0.0.1_16537-1-trace.log
{code}

[h2o-ops]

JIRA Issue Details

Jira Issue: PUBDEV-7992
Assignee: hannah.tillman
Reporter: Erin LeDell
State: Resolved
Fix Version: 3.32.1.1
Attachments: N/A
Development PRs: Available

[h2o-ops]

Linked PRs from JIRA

#5313
#5386