docs: remove deprecated npm set-script

Author: typicode

.github/README.md

@@ -17,7 +17,7 @@ npm install husky -D
 Edit `package.json > prepare` script and run it once:
 
 ```sh
-npm set-script prepare "husky install"
+npm pkg set scripts.prepare="husky install"
 npm run prepare
 ```
 

docs/README.md

@@ -262,7 +262,7 @@ npm ci --omit=dev --ignore-scripts
 Alternatively, you can specifically disable `prepare` script with
 
 ```shell
-npm set-script prepare ""
+npm pkg delete scripts.prepare
 npm ci --omit=dev
 ```