adding Plugin API reference

[mhmohona]

Explanation

Added new page for Plugin API Referee with following content -

• WasmEdge Plugin API Reference
  • Loading a WasmEdge plugin
  • Registering the plugin API
  • Importing the plugin modules
  • Sample application that uses a WasmEdge plugin
  • Examples of WasmEdge Plug-ins
    • Overview of the WasmEdge Plug-ins
    • WasmEdge-Process Plug-in
    • WASI-Crypto Plug-in
    • WASI-NN Plug-in with OpenVINO backend
    • WASI-NN Plug-in with PyTorch backend
    • WASI-NN Plug-in with TensorFlow-Lite backend
    • WasmEdge-HttpsReq Plug-in

Related issue - #85

What type of PR is this

/kind documentation

Proposed Changes

[alabulei1]

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 05e66618cda94f06b37c0161cd4785d0fcd61041

The key change made in this pull request is the addition of a new markdown page titled "api_reference.md", which provides information on how to load, register, and import WasmEdge plugins through API. The page also includes an overview of the WasmEdge plugins that are currently released and a sample application that uses a WasmEdge plugin. The new page has been added to the "contribute/plugin" directory and also included in the sidebar of the WasmEdge documentation.

The patch does not contain any identifiable potential problem. However, after reviewing the page, it might be helpful to add some examples in the "Overview of the WasmEdge Plug-ins" section to illustrate the functionalities of each plugin. Additionally, it could be helpful to mention the programming language(s) supported for writing WasmEdge plugins.