Added Broken link validation feature

[thebiggest0]

validate-broken-link.js

• Add a new JavaScript file containing functions to validate broken link

data.json

• Add a new JSON file to keep a record of all broken links and the dates associated with each

package.json and package-lock.json

• Update markdown-link-check dependencies to the newest version that reads and writes to data.json

GitHub workflows

• Update node.js.yml and link-check.yml to allow GitHub actions to commit changes to data.json when broken links are detected