Refactor TOC for Azure Operator Service Manager documentation

Updated the Azure Operator Service Manager documentation structure, including renaming sections and adjusting item hierarchies.

Author: msftadam

articles/operator-service-manager/TOC.yml

@@ -10,14 +10,14 @@
 - name: Concepts
   expanded: false
   items:
-  - name: Basic Concepts
+  - name: Getting Started
     expanded: false
     items:
       - name: Role-Based Persona Model
         href: roles-interfaces.md
       - name: Tenants, Subscriptions and Regions
         href: publisher-resource-preview-management.md
-      - name: Get Started with Onboarding and Deploying
+      - name: Onboarding and Deploying Basics
         href: best-practices-onboard-deploy.md
   - name: Publisher Best Practices
     expanded: false
@@ -151,3 +151,4 @@
 
 
 
+