Architecture docs

[zees-dev]

Description

This pull request introduces comprehensive documentation for the Blockless Rust SDK in the docs/architecture.md file.
It provides an overview of the SDK's features, installation, core concepts, system architecture, development workflow, and available modules.
The documentation aims to guide developers in using the SDK to build WebAssembly (WASM) applications for the bls-runtime environment.

Key Changes:

Documentation for SDK Features and Usage:

• Added installation instructions, including how to add the blockless-sdk to a Rust project and manage optional features like serde.
• Explained core concepts such as the permission-based model of bls-runtime and compiling Rust code to the wasm32-wasip1 target.

Architectural Overview:

• Provided a high-level architectural diagram and explanation of the SDK's role as a bridge between Rust application code and the WebAssembly runtime.
• Detailed the runtime execution flow, including how host function calls are routed through driver modules to interact with external resources.

Development Workflow:

• Outlined the typical lifecycle of developing, compiling, configuring, and running a Blockless-enabled WASM application, supported by a mermaid diagram.

SDK Modules and Capabilities:

• Documented the SDK's modules