Fix header levels.

docs/en/Getting-Started-Create-Solution.md

@@ -41,19 +41,19 @@ abp new Acme.BookStore{{if UI == "NG"}} -u angular{{else if UI == "Blazor"}} -u
 
 > [ABP CLI document](./CLI.md) covers all of the available commands and options.
 
-## Mobile Development
+### Mobile Development
 
 If you want to include a [React Native](https://reactnative.dev/) project in your solution, add `-m react-native` (or `--mobile react-native`) argument to project creation command. This is a basic React Native startup template to develop mobile applications integrated to your ABP based backends.
 
 See the [Getting Started with the React Native](Getting-Started-React-Native.md) document to learn how to configure and run the React Native application.
 
-### The Solution Structure
+## The Solution Structure
 
 The solution has a layered structure (based on the [Domain Driven Design](Domain-Driven-Design.md)) and contains unit & integration test projects. See the [application template document](Startup-Templates/Application.md) to understand the solution structure in details. 
 
 {{ if DB == "Mongo" }}
 
-#### MongoDB Transactions
+## MongoDB Transactions
 
 The [startup template](Startup-templates/Index.md) **disables** transactions in the `.MongoDB` project by default. If your MongoDB server supports transactions, you can enable it in the *YourProjectMongoDbModule* class's `ConfigureServices` method: