Yii 3 → Yii3 and typo fix

Author: samdark

src/guide/intro/upgrade-from-v2.md

@@ -3,9 +3,9 @@
 > If you haven't used Yii2, you can skip this section and get directly to "[getting started](../start/prerequisites.md)"
 > section.
 
-While sharing some common ideas and values, Yii 3 is conceptually different from Yii 2. There is no easy upgrade
+While sharing some common ideas and values, Yii3 is conceptually different from Yii 2. There is no easy upgrade
 path, so first [check maintenance policy and end-of-life dates for Yii 2](https://www.yiiframework.com/release-cycle)
-and consider starting new projects on Yii 3 while keeping existing ones on Yii 2.
+and consider starting new projects on Yii3 while keeping existing ones on Yii 2.
 
 ## PHP requirements
 
@@ -26,12 +26,12 @@ Yii3 requires PHP 8.2 or above. As a result, there are language features used th
 
 ## Preliminary refactoring
 
-It's a good idea to refactor your Yii 2 project before porting it to Yii 3. That would both make porting easier
-and benefit the project in question while it's not moved to Yii 3 yet.
+It's a good idea to refactor your Yii 2 project before porting it to Yii3. That would both make porting easier
+and benefit the project in question while it's not moved to Yii3 yet.
 
 ### Use DI instead of the service locator
 
-Since Yii 3 is forcing you to inject dependencies, it's a good idea to prepare and switch from using
+Since Yii3 is forcing you to inject dependencies, it's a good idea to prepare and switch from using
 service locator (`Yii::$app->`) to [DI container](https://www.yiiframework.com/doc/guide/2.0/en/concept-di-container).
 
 If usage of DI container is problematic for whatever reason, consider moving all calls to `Yii::$app->` to controller
@@ -41,7 +41,7 @@ See [Dependency injection and container](../concept/di-container.md) for an expl
 
 ### Introduce repositories for getting data
 
-Since Active Record isn't the only way to work with a database in Yii 3, consider introducing repositories that would
+Since Active Record isn't the only way to work with a database in Yii3, consider introducing repositories that would
 hide details of getting data and gather them in a single place. You can later redo it: 
 
 ```php
@@ -67,7 +67,7 @@ that's all the business logic has to go to framework-independent classes.
 
 ### Move more into components
 
-Yii 3 services are conceptually similar to Yii 2 components, so it's a good idea to move reusable parts of your application
+Yii3 services are conceptually similar to Yii 2 components, so it's a good idea to move reusable parts of your application
 into components.
 
 ## Things to learn
@@ -84,7 +84,7 @@ It's a good idea to learn how to use it and use it for your own projects since i
 ### Environment variables
 
 Yii3 application templates are using [environment variables](https://en.wikipedia.org/wiki/Environment_variable)
-to configure pars of the application. The concept is [very handy for Dockerized applications](https://12factor.net/)
+to configure parts of the application. The concept is [very handy for Dockerized applications](https://12factor.net/)
 but might be alien to users of Yii 1.1 and Yii 2.
 
 ### Handlers
@@ -97,4 +97,4 @@ are similar to controllers but different.
 Suggested Yii3 application structure is different from Yii 2. 
 It's described in [application structure](../structure/overview.md).
 
-Despite that, Yii3 is flexible, so it's still possible to use a structure similar to Yii 2 with Yii 3.
+Despite that, Yii3 is flexible, so it's still possible to use a structure similar to Yii 2 with Yii3.

src/guide/structure/application.md

@@ -1,6 +1,6 @@
 # Application
 
-The primary purpose of the web application and its runner in Yii 3 is to process requests to get responses.
+The primary purpose of the web application and its runner in Yii3 is to process requests to get responses.
 
 Typically, the runtime consists of: