docs: add 3d mesh part

docs/guide/2d/container.md

@@ -1,7 +1,7 @@
 # Container
 
-Every [`FComponent`](/api/2d/classes/FComponent) in `@fibbojs/2d` has a `container` property that corresponds to the [PixiJS Container](https://pixijs.com/8.x/guides/components/containers) that will be used to render the component.
+Every [`FComponent`](/api/2d/classes/FComponent) in `@fibbojs/2d` has a `container` attribute that corresponds to the [PixiJS Container](https://pixijs.com/8.x/guides/components/containers) that will be used to render the component.
 
 This is either a [Graphics](https://pixijs.com/8.x/guides/components/graphics) (for rectangles, circles,...) or a [Sprite](https://pixijs.com/8.x/guides/components/sprites) (basically an image) depending on the component.
 
-Unless you have a good reason to do so, you should not modify the `container` directly, but use the provided methods instead.
+Unless you have a good reason to do so, you should not modify the `container` attribute directly, but use the provided methods instead.

docs/guide/3d/mesh.md

@@ -1 +1,11 @@
 # Mesh
+
+Every [`FComponent`](/api/3d/classes/FComponent) in `@fibbojs/3d` has a `mesh` attribute that corresponds to the [Three.js Mesh](https://threejs.org/docs/#api/en/objects/Mesh) that will be used to render the component.
+
+It will either be one of [classic polyhedrons](https://threejs.org/docs/#api/en/geometries/PolyhedronGeometry) (like a [BoxGeometry](https://threejs.org/docs/#api/en/geometries/BoxGeometry) or a [SphereGeometry](https://threejs.org/docs/#api/en/geometries/SphereGeometry)) or a [custom 3D model](https://threejs.org/docs/#manual/en/introduction/Loading-3D-models).
+
+Unless you have a good reason to do so, you should not modify the `mesh` attribute directly, but use the provided methods instead.
+
+## What is a mesh ?
+
+A [mesh](https://en.wikipedia.org/wiki/Polygon_mesh) is a 3D object that is composed of vertices, edges, and faces. It is the basic building block of any 3D computer graphics.