The readme(s) use the GH permalink https://github.com/DefinitelyTyped/DefinitelyTyped/blob/1253faabf5e0d2c5470db6ea87795d7f96fef7e2/types/history/v2/tsconfig.json in an example. It appears that remark-validate-link (powered by hosted-git-info) recognizes that this is from our GH repo and concludes that the appropriate file to validate is types/history/v2/tsconfig.json, which does not exist.

remark-validate-link doesn't support much configuration, but it seems possible that a .remarkc file could specify its hostname setting to override the inferred value and prevent remark-validate-link from attempting to validate absolute paths as though they were relative. Note, however, that doing so would cause it to miss bad URLs like https://github.com/DefinitelyTyped/DefinitelyTyped/blob/master/types/history/v2/tsconfig.json (which actually doesn't exist). The correct fix would probably require passing a setting to hosted-git-info, possible nocommitish.