improve source code documentation

[hulxv]

Introduction

The source code documentation is very poor and needs a lot of work to help new contributors get into the project and understand it. We will use rustdoc and document the source code directly. Also, We will need to add some comments to explain the complex process and the framework`s architecture.

Tasks

• docs: Explain the framework's architecture #19

• docs: document metassr-utils #13

• docs: document metassr-bundler  #14

• docs: document metassr-build #15

• docs: document metassr-server #16

• docs: document html-generator #17

• docs: document metassr-cli #18