docs: add yarn and pnpm install commands (#163)

* docs(index.md): add yarn command in index.md

Add yarn install command in the installation section of guide/index.md.

* fix: docs/guide/index.md suggestion

Co-authored-by: Shinigami <chrissi92@hotmail.de>

* docs(readme.md): add yarn/pnpm install commands

Co-authored-by: fncolon <fncolon@pm.me>

Co-authored-by: Shinigami <chrissi92@hotmail.de>
Co-authored-by: fncolon <fncolon@pm.me>

README.md

@@ -10,7 +10,19 @@ Generate massive amounts of fake data in the Browser and Node.js.
 Please replace your `faker` dependency with `@faker-js/faker`. This is the official, stable fork of Faker.
 
 ```shell
-npm install @faker-js/faker -D
+npm install @faker-js/faker --save-dev
+```
+
+or
+
+```shell
+yarn add @faker-js/faker --dev
+```
+
+or
+
+```shell
+pnpm add @faker-js/faker --save-dev
 ```
 
 ### Typescript Support

docs/guide/index.md

@@ -25,6 +25,18 @@ Install it as a Dev Dependency using your favorite package manager.
 npm install @faker-js/faker --save-dev
 ```
 
+or
+
+```shell
+yarn add @faker-js/faker --dev
+```
+
+or
+
+```shell
+pnpm add @faker-js/faker --save-dev
+```
+
 ## Usage
 
 ### Node.js