[*] update release documentation

[pashagolub]

The upcoming release adds several user-visible capabilities, but the public docs did not describe them consistently yet. This refresh brings the README and MkDocs pages back in sync with the current release behavior so users can discover and use the new options directly from the documentation.

What changed

• refreshed the feature summaries in the README and docs index to mention task enable/disable support, YAML-based configuration, OpenTelemetry support, and Docker arm64 availability
• updated the CLI documentation for repeatable --file usage and the YAML-specific --replace and --validate flags
• expanded the YAML and task documentation with examples for loading multiple startup files and disabling individual tasks with live: false
• clarified Docker image availability for both linux/amd64 and linux/arm64

[coveralls]

Coverage Report for CI Build 29903452202

Coverage decreased (-0.04%) to 89.965%

Details

• Coverage decreased (-0.04%) from the base build.
• Patch coverage: No coverable lines changed in this PR.
• 3 coverage regressions across 1 file.

Uncovered Changes

No uncovered changes found.

Coverage Regressions

3 previously-covered lines in 1 file lost coverage.

File	Lines Losing Coverage	Coverage
internal/scheduler/interval_chain.go	3	82.61%

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Coverage Stats

Relevant Lines:	2302
Covered Lines:	2071
Line Coverage:	89.97%
Coverage Strength:	1.02 hits per line

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💛 - Coveralls