Add category-specific documentation view and management

- Introduce routes and controller actions for displaying and managing documentation by category.
- Adjust views to incorporate category-specific information and actions.
- Update services to handle category retrieval and validation.
- Add localized strings for new functionality in English and Russian.

app/application/lang/en.json

@@ -38,6 +38,9 @@
     "Connection Timed Out": "Connection Timed Out",
     "Continue": "Continue",
     "Create": "Create",
+    "Create documentation": "Create documentation",
+    "Create category": "Create category",
+    "Create version documentation": "Create a version of the documentation",
     "Create :name": "Create :name",
     "Created": "Created",
     "Delete": "Delete",