docs: add readme (#38)

* docs: add readme

Signed-off-by: Mauran <thomas.mauran@etu.umontpellier.fr>

---------

Signed-off-by: Mauran <thomas.mauran@etu.umontpellier.fr>
Signed-off-by: Matéo Fernandez <mateo.fernandez@etu.umontpellier.fr>
Co-authored-by: Matéo Fernandez <mateo.fernandez@etu.umontpellier.fr>
Co-authored-by: Alexandre Sollier <github@kuruyia.net>

README.md

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+<div style="text-align:center">
+    <h1> Cloudlet</h1>
+    <p>The almost fast FaaS</p>
+    <img src="./assets/demo.gif" alt="Demo" />
+</div>
+
+## Table of Contents
+
+- [Table of Contents](#table-of-contents)
+- [Prerequisites](#prerequisites)
+- [Run Locally](#run-locally)
+  - [Clone the project](#clone-the-project)
+  - [Setup](#setup)
+  - [Start the VMM](#start-the-vmm)
+  - [Run the API](#run-the-api)
+  - [Send the request using the CLI](#send-the-request-using-the-cli)
+- [Architecture](#architecture)
+- [Config file](#config-file)
+
+## Prerequisites
+
+Install the dependencies. On Debian/Ubuntu:
+
+```bash
+apt install build-essential cmake pkg-config libssl-dev flex bison libelf-dev
+```
+
+Then, configure the Rust toolchain and install [Just](https://github.com/casey/just):
+
+```bash
+rustup target add x86_64-unknown-linux-musl
+cargo install just
+```
+
+Finally, install [the protobuf compiler](https://github.com/protocolbuffers/protobuf?tab=readme-ov-file#protobuf-compiler-installation).
+
+## Run Locally
+
+### Clone the project
+
+```bash
+git clone https://github.com/virt-do/cloudlet
+```
+
+### Setup
+
+Go to the project directory:
+
+```bash
+cd cloudlet
+```
+
+Create a TOML config file or update the [existing one](./src/cli/examples/config.toml):
+
+```bash
+cat << EOF > src/cli/examples/config.toml
+workload-name = "fibonacci"
+language = "rust"
+action = "prepare-and-run"
+
+[server]
+address = "localhost"
+port = 50051
+
+[build]
+source-code-path = "$(readlink -f ./src/cli/examples/main.rs)"
+release = true
+EOF
+```
+
+Make sure to update the `source-code-path` to the path of the source code you want to run.
+Use an absolute path.
+
+[Here](#config-file) are more informations about each field
+
+### Start the VMM
+
+> [!WARNING]
+> Make sure to replace `CARGO_PATH` environment variable with the path to your cargo binary
+> 
+> ```bash
+> export CARGO_PATH=$(which cargo)
+> ```
+
+```bash
+sudo -E capsh --keep=1 --user=$USER --inh=cap_net_admin --addamb=cap_net_admin -- -c  'RUST_BACKTRACE=1 '$CARGO_PATH' run --bin vmm -- grpc'
+```
+
+### Run the API
+
+```bash
+cargo run --bin api
+```
+
+### Send the request using the CLI
+
+```bash
+cargo run --bin cli -- run --config-path src/cli/examples/config.toml
+```
+
+> [!NOTE]
+> If it's your first time running the request, `cloudlet` will have to compile a kernel and an initramfs image.
+> This will take a while, so make sure you do something else while you wait...
+
+## Architecture
+
+Here is a simple sequence diagram of Cloudlet:
+
+```mermaid
+sequenceDiagram
+    participant CLI
+    participant API
+    participant VMM
+    participant Agent
+
+    CLI->>API: HTTP Request /run
+    API->>VMM: gRPC Request to create VM
+    VMM->>Agent: Creation of the VM
+    VMM->>Agent: gRPC Request to the agent
+    Agent->>Agent: Build and run code
+    Agent-->>VMM: Stream Response
+    VMM-->>API: Stream Response
+    API-->>CLI: HTTP Response
+```
+
+1. The CLI sends an HTTP request to the API which in turn sends a gRPC request to the VMM
+2. The VMM then creates a VM
+3. When a VM starts it boots on the agent which holds another gRPC server to handle requests
+4. The agent then builds and runs the code
+5. The response is streamed back to the VMM and then to the API and finally to the CLI.
+
+## Config file
+| Field | Description | Type |
+| --- | --- | --- |
+| workload-name | Name of the workload you wanna run | String |
+| language | Language of the source code | String enum: rust, python node |
+| action | Action to perform | String enum: prepare-and-run |
+| server.address | Address of the server (currently not used) | String |
+| server.port | Port of the server (currently not used) | Integer |
+| build.source-code-path | Path to the source code on your local machine | String |
+| build.release | Build the source code in release mode | Boolean |