refactoring: build and testing

[laiso]

Changes

• Simplified the CLI entry point.
• Updated tests to match the latest configuration.

Details

1. Removed bin/index.js and modified bin/site2pdf.js to call the main function directly.
2. Updated the version in package.json from 0.1.0 to 0.1.1 and changed the bin entry from bin/index.js to bin/site2pdf.js.
3. Made the following changes to index.ts:
   • Added showHelp function.
   • Added useBrowserContext function.
   • Modified generatePDF function to use the BrowserContext type.
   • Updated the main function to use useBrowserContext.
4. Imported describe, it, and expect from @jest/globals in cli.test.ts.
5. Updated index.test.ts to use the BrowserContext type.
6. Changed the exclude entry in tsconfig.json from **/*.spec.ts to **/*.test.ts.