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/userManuals/viewer/Hotkeys/hotkeys.md

@@ -0,0 +1,10 @@
+# Hotkeys
+
+To open the hotkey assignment panel, you can click on the Preferences gear on the
+top right side of the viewer.
+
+![user-hotkeys](../../../assets/img/user-hotkeys.png)
+
+Below, you can see the default hotkeys key bindings:
+
+![user-hotkeys-default](../../../assets/img/user-hotkeys-default.png)