chore: removes redundant type definition install instruction (#2114)

Author: bfdes

docs/user/install.md

@@ -13,15 +13,15 @@ You can install `ts-jest` and dependencies all at once with the following comman
 Using `npm`:
 
 ```sh
-npm install --save-dev jest typescript ts-jest @types/jest
+npm install --save-dev jest typescript ts-jest
 ```
 
 </div><div class="col-md-6" markdown="block">
 
 Using `yarn`:
 
 ```sh
-yarn add --dev jest typescript ts-jest @types/jest
+yarn add --dev jest typescript ts-jest
 ```
 
 </div></div>