Concise README, and change IAgenticaTokenUsage

[samchon]

This pull request includes various updates to the agentica project, focusing on improving documentation, updating package versions, and renaming properties for clarity. The most significant changes are summarized below:

Documentation Improvements:

• README.md: Enhanced the description of the agentica library for better clarity and readability, including a more concise explanation of its capabilities and a simplified code example.

Version Updates:

• package.json: Updated the version of the @agentica/station package from 0.8.0 to 0.8.1.

Property Renaming for Clarity:

• packages/core/src/internal/AgenticaTokenUsageAggregator.ts: Renamed the kind property to type in the IAgenticaTokenUsage.IComponent interface to improve clarity. [1] [2]
• packages/core/src/structures/IAgenticaTokenUsage.ts: Updated the IAgenticaTokenUsage.IComponent interface to use type instead of kind for the discriminator property.

[samchon]

Everything is ready