[Example] ggml: add gemma support

[hydai]

This should be merged after the WasmEdge ggml plugin is updated.

Related issue: https://github.com/WasmEdge/WasmEdge/pull/3230

[juntao]

Hello, I am a code review bot on flows.network. Here are my reviews of code commits in this PR.

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Commit 344a2f660a947b552bea8637d20736815ba5670c

Key Changes:

1. Added Gemma support to the ggml library.
2. Three new files were created: Cargo.toml, main.rs, and wasmedge-ggml-gemma.wasm.
3. The Cargo.toml file defines package information and dependencies, including serde_json and wasi-nn.
4. The main.rs file contains implementation details for Gemma support, including reading input, setting context data, and handling inference execution.
5. The wasmedge-ggml-gemma.wasm file contains binary data related to the Gemma support.

Potential Problems:

1. Security: The code should be reviewed for potential security vulnerabilities, especially when handling input from user prompts.
2. Error Handling: Ensure that error handling mechanisms are robust and cover all potential failure scenarios.
3. Documentation: Consider adding or enhancing code comments and documentation to improve code readability and maintainability.
4. Performance: Check the code for any performance bottlenecks, especially during computation and data handling processes.
5. Testing: Verify that the new Gemma support functions as expected by writing comprehensive tests.

Overall, the changes seem to be primarily focused on adding Gemma support to the ggml library. The implementation adds new functionality but may require further review and refinement to address potential issues before merging.