Update documentation to remove Yarn references.

docs/en/framework/real-time/signalr.md

@@ -55,11 +55,9 @@ Client side installation depends on your UI framework / client type.
 Run the following command in the root folder of your web project:
 
 ```bash
-yarn add @abp/signalr
+npm install @abp/signalr
 ```
 
-> This requires to [install yarn](https://yarnpkg.com/) if you haven't install before.
-
 This will add the `@abp/signalr` to the dependencies in the `package.json` of your project:
 
 ```json

docs/en/framework/ui/mvc-razor-pages/client-side-package-management.md

@@ -3,9 +3,8 @@
 
 ABP can work with any type of client side package management systems. You can even decide to use no package management system and manage your dependencies manually.
 
-However, ABP works best with **NPM/Yarn**. By default, built-in modules are configured to work with NPM/Yarn.
+However, ABP works best with **NPM**. By default, built-in modules are configured to work with NPM.
 
-Finally, we suggest the [**Yarn**](https://classic.yarnpkg.com/) over the NPM since it's faster, stable and also compatible with the NPM.
 
 ### @ABP NPM Packages
 
@@ -35,14 +34,12 @@ It's suggested to depend on a standard package instead of directly depending on
 
 #### Package Installation
 
-After depending on a NPM package, all you should do is to run the **yarn** command from the command line to install all the packages and their dependencies:
+After depending on a NPM package, all you should do is to run the **npm install** command from the command line to install all the packages and their dependencies:
 
 ```bash
-yarn
+npm install
 ```
 
-Alternatively, you can use `npm install` but [Yarn v1.22+ (not v2)](https://classic.yarnpkg.com/en/docs/install) is suggested as mentioned before.
-
 #### Package Contribution
 
 If you need a third-party NPM package that is not in the standard set of packages, you can create a Pull Request on the Github [repository](https://github.com/volosoft/abp). A pull request that follows these rules is accepted:
@@ -57,7 +54,7 @@ See current standard packages for examples.
 
 ### Mapping The Library Resources
 
-Using NPM packages and NPM/Yarn tool is the de facto standard for client side libraries. NPM/Yarn tool creates a **node_modules** folder in the root folder of your web project.
+Using NPM packages and NPM tool is the de facto standard for client side libraries. NPM tool creates a **node_modules** folder in the root folder of your web project.
 
 Next challenge is copying needed resources (js, css, img... files) from the `node_modules` into a folder inside the **wwwroot** folder to make it accessible to the clients/browsers.
 

docs/en/tutorials/book-store/part-01.md

@@ -34,8 +34,6 @@ For such cases, run the `abp install-libs` command on the root directory of your
 abp install-libs
 ```
 
-> We suggest you install [Yarn v1.22+ (not v2)](https://classic.yarnpkg.com/en/docs/install) to prevent possible package inconsistencies, if you haven't installed it yet.
-
 ## Create the Book Entity
 
 **Domain layer** in the startup template is separated into two projects: