[docs]Update Fresh project setup commands and Hero component configuration

[SisyphusZheng]

This pull request updates documentation and example code to reflect a new project initialization command and improves developer experience by clarifying the development workflow. It also simplifies the Hero component interface and updates the copy area to use the new init command.

Documentation and usage updates:

• Updated the recommended Fresh project initialization command in README.md and the homepage Hero component to use deno run -Ar jsr:@fresh/init instead of the previous URL-based command. [1] [2]
• Changed the development workflow documentation in www/README.md to use deno task dev instead of deno task start, clarifying the command for starting the development server.

Code simplification:

• Simplified the Hero component by removing the origin prop, as it is no longer needed with the static init command.

[marvinhagemeister]

A bit unsure if we should merge it now or wait until 2.0 is officially released.

[SisyphusZheng]

A bit unsure if we should merge it now or wait until 2.0 is officially released.

I personally think everyone is eagerly waiting for V2, and the changes you've driven are significant. At least from my perspective, it would be better to let everyone feel (the changes) sooner.