Add logging to file, std output isn’t enough

Full scope: https://github.com/dgroup/lazylead/milestone/25?closed=1

See #366, release log:

• f2b9d07 by @dgroup: #366: Add file appender with r...
• e486c85 by @dgroup: #371: Send *.zip archive as at...
• 6fa00fc by @dgroup: #370: Unauthorized due date mo...
• 842a989 by @dgroup: Merge remote-tracking branch '...
• a47aef7 by @dgroup: #373: Self assignment is allow...
• f144080 by @dependabot[bot]: Update rubocop-performance req...
• 113b144 by @dgroup: #367: invalid byte sequence in...
• 6e682db by @dgroup: #368: undefined method `[]' fo...
• 94506ba by @dependabot[bot]: Update rubocop requirement fro...
• 283ab50 by @dependabot[bot]: Update faraday requirement fro...
• 5c15bd3 by @dgroup: #363: simplify if statement
• 4ba35f8 by @dgroup: #363: categorize loading.erb p...
• 1db2e5c by @dgroup: #362: fix loading.erb hard cod...
• c95a81b by @dgroup: #364: support custom fields

Released by Rultor 1.69.1, see build log