Add JSON/Markdown output formats and CLI support

[Copilot]

• Add src/lib/textOutput.ts with msgToRecord, recordsToJson, recordsToMarkdown functions
• Add src/textMain.ts for JSON/Markdown output mode (no Google Sheets dependency)
• Add src/cli.ts as CLI entry point (parses CLI flags, sets env vars, calls appropriate main)
• Update src/settings.ts to support direct env vars (e.g. SLACK_TOKEN) as fallback to INPUT_* vars, and add format field
• Update src/action.ts to check settings.format and call textMain for json/markdown formats, with format validation
• Update action.yml to add optional format input (default: gsheet); make Google creds/folderId optional
• Update deno.json to add @std/cli import and CLI task
• Update setup-deno action to v2.0.3 (e95548e)

Original prompt

google sheet への出力だけでなく、json 出力、 markdown 出力も可能に。
基本的に cli で実行可能にしつつ、 github action も提供する形に。

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[kuboon]

@copilot
ついでにここ最新化して

name: Setup Deno
uses: denoland/setup-deno@27e0043 #v2.0.2

[Copilot]

@copilot
ついでにここ最新化して
...

Updated to denoland/setup-deno@e95548e56dfa95d4e1a28d6f422fafe75c4c26fb #v2.0.3 in commit 20a9865.