feat: Added documentation for OHIF-v3 (#2450)

* Added docs with new screenshots

* Added doc to architecture

* Added documentations to various extension modules

* Added more documentation to modes

* Added docs to managers

* Added docs for services

* Fixed deployment docs

* Added white labelling documentation

* Added i18n docs and measurement export

docs/latest/extensions/lifecycle/on-mode-enter.md

@@ -0,0 +1,29 @@
+# Lifecycle Hook: onModeEnter
+
+If an extension defines the `onModeEnter` lifecycle hook, it is called
+when a new mode is enters, or a mode's data or datasource is switched.
+
+For instance, in DICOM structured report extension (`dicom-sr`), we are using
+`onModeEnter` to re-create the displaySets after a new mode is entered.
+
+_Example `onModeEnter` hook implementation_
+
+```js
+export default {
+  id: 'org.ohif.dicom-sr',
+
+  onModeEnter({ servicesManager}) {
+    const { DisplaySetService } = servicesManager.services;
+    const displaySetCache = DisplaySetService.getDisplaySetCache();
+
+    const srDisplaySets = displaySetCache.filter(
+      ds => ds.SOPClassHandlerId === SOPClassHandlerId
+    );
+
+    srDisplaySets.forEach(ds => {
+      // New mode route, allow SRs to be hydrated again
+      ds.isHydrated = false;
+    });
+  },
+};
+```