delete all empty directories recursively

See #86, release log:

• 507080f by @yegor256: Revert "#88 not shallow clone"...
• 6d79294 by @yegor256: #88 not shallow clone
• 14edd01 by @yegor256: #86 shellcheck fixed
• 1ecb96e by @yegor256: #86 pylint fixed
• e6503b9 by @yegor256: #86 jpeek files moved to /temp
• 624209d by @renovate[bot]: Update dependency pylint to v3
• fa3d8e0 by @yegor256: #86 sort
• 8768b63 by @yegor256: #86 recursively
• 5cbc46b by @yegor256: #86 delete but not recursively
• 59b8e89 by @yegor256: #85 exclude from ZIP
• 5ff7e75 by @yegor256: #85 lint
• e9d5dfd by @yegor256: #85 to-csv
• 4902041 by @yegor256: #85 jobs into /temp
• 12c8a78 by @yegor256: #85 join
• 3be09d4 by @yegor256: #85 float.sh
• fc87848 by @yegor256: #85 show more
• 9a80ead by @yegor256: #85 show metrics total
• fe63e5e by @yegor256: #85 puzzle removed
• e2bc810 by @yegor256: #85 all clean
• 04cbbfe by @yegor256: #85 fix
• and 24 more...

Released by Rultor 2.0-SNAPSHOT, see build log