Merged PR 167: Add Flex and fix bugs (read desc)

Note: The branch name does not fit the new features.

- Implement Flex with simplex
- Enable rigid body by default (removed IsRigidBody property) <=== possibly a bad idea
- Sort children in add and update properties
- Implement MaxWidth
- Add more docs

Fixes :
- .env.production url
- Symbols: not blocking the linked container when the parent is moving

src/Components/Editor/Behaviors/RigidBodyBehaviors.ts

@@ -9,6 +9,7 @@
 import Swal from 'sweetalert2';
 import { IContainerModel } from '../../../Interfaces/IContainerModel';
 import { ISizePointer } from '../../../Interfaces/ISizePointer';
+import { PushContainers } from './FlexBehaviors';
 
 /**
  * "Transform the container into a rigid body"
@@ -23,6 +24,7 @@ export function ApplyRigidBody(
   container: IContainerModel
 ): IContainerModel {
   container = constraintBodyInsideParent(container);
+  container = PushContainers(container);
   container = constraintBodyInsideUnallocatedWidth(container);
   return container;
 }
@@ -183,7 +185,6 @@ export function constraintBodyInsideUnallocatedWidth(
         showConfirmButton: false,
         timer: 5000
       });
-      container.properties.isRigidBody = false;
       return container;
     }
 
@@ -238,8 +239,7 @@ function getAvailableWidths(
 
     // Ignore the exception
     // And we will also only uses containers that also are rigid or are anchors
-    if (child === exception ||
-      (!child.properties.isRigidBody && !child.properties.isAnchor)) {
+    if (child === exception) {
       continue;
     }
     const childX = child.properties.x;