Implement events for external use + Rename interfaces with a I prefix + add some documentation (#26)

Implement events for external use
Rename interfaces with a I prefix
Add some documentation

Co-authored-by: Eric NGUYEN <enguyen@techform.fr>
Reviewed-on: https://git.siklos-chaneru.duckdns.org/Siklos/svg-layout-designer-react/pulls/26

src/Events/EditorEvents.ts

@@ -0,0 +1,26 @@
+import { IEditorState } from '../Interfaces/IEditorState';
+import { IHistoryState } from '../Interfaces/IHistoryState';
+
+const getEditorState = (editorState: IEditorState): void => {
+  const customEvent = new CustomEvent<IEditorState>('getEditorState', { detail: editorState });
+  document.dispatchEvent(customEvent);
+};
+
+const getCurrentHistoryState = (editorState: IEditorState): void => {
+  const customEvent = new CustomEvent<IHistoryState>(
+    'getCurrentHistoryState',
+    { detail: editorState.history[editorState.historyCurrentStep] });
+  document.dispatchEvent(customEvent);
+};
+
+export interface IEditorEvent {
+  name: string
+  func: (editorState: IEditorState) => void
+}
+
+const events: IEditorEvent[] = [
+  { name: 'getEditorState', func: getEditorState },
+  { name: 'getCurrentHistoryState', func: getCurrentHistoryState }
+];
+
+export default events;