get rid of ANTLR

See #75, release log:

• 3eb0ee6 by @yegor256: badge off
• fcd74de by @yegor256: ico
• a895b23 by @yegor256: year up
• 297ad04 by @rultor: Merge branch '__rultor'
• 24dee5d by @maxonfjvipon: fix(#75): got rid of antrl
• f13ba8e by @renovate[bot]: chore(deps): update dependency...
• 896f889 by @renovate[bot]: fix(deps): update dependency c...
• a9d6908 by @yegor256: new location of codecov/codeco...
• ac8e194 by @renovate[bot]: chore(deps): update dependency...
• 2f1b152 by @yegor256: PDD GitHub Action to volodya-l...
• 310d8bb by @yegor256: New PDD GitHub Action location
• 36c4cf9 by @renovate[bot]: chore(deps): update dependency...
• ee8c2ac by @renovate[bot]: chore(deps): update actions/se...
• 5d584f8 by @yegor256: extra test
• f3a8d0f by @yegor256: Merge pull request #166 from y...
• d96d789 by @rultor: new version in README
• 9a3ca1c by @renovate[bot]: chore(deps): update dependency...

Released by Rultor 2.0-SNAPSHOT, see build log