✨(sdk) add sdk projects

It includes a consumer project which is simply a demo app. The sdk
project includes the first version of the SDK, with a light React
implementation. The first version lays down the foundations of
the iframe sdk framework. The npm package logic is also already
ready to be published.

src/sdk/library/README.md

@@ -0,0 +1,42 @@
+<div align="center">
+
+# 🎥 Visio SDK
+
+**Easily add a button to create visio link to your product**
+
+<img src="docs/demo.gif" alt="" width="400" />
+
+<br/>
+<br/>
+<strong>... that also handles seamless authentication out of the box</strong>
+<br/>
+<br/>
+
+<img src="docs/demo_loggedout.gif" alt="" />
+
+<br/>
+<br/>
+<strong>As simple as</strong>
+<br/>
+<br/>
+
+</div>
+
+```ts
+import { VisioCreateButton } from "@gouvfr-lasuite/visio-sdk";
+
+function App() {
+  const [roomUrl, setRoomUrl] = useState();
+
+  return <VisioCreateButton onRoomCreated={setRoomUrl} />;
+}
+```
+
+## Installation
+
+To install, you can use npm or yarn:
+
+```
+$ npm install --save @gouvfr-lasuite/visio-sdk
+$ yarn add @gouvfr-lasuite/visio-sdk
+```