This remark-lint rule ensures that there will be no duplicate links URL in the list

Checks only duplicate URL, which helps to get rid of duplicates with the same link names or with different ones. The main policy is not to duplicate links to the same resources

<!-- Invalid -->
[link-1](https://link-1)
[link-2](https://link-1)
<!-- Valid -->
[link](https://link-1)

npm install -g remark-cli
npm install remark-lint remark-lint-alphabetize-lists

Then, set up your .remarkrc:

{
  "plugins": [
    "lint",
    "lint-double-link"
  ]
}

Now you can use the following command to run the lint:

remark xxx.md

npm install -g remark-cli
npm install remark-lint remark-lint-double-link
remark -u lint -u lint-double-link xxx.md