doc: fix broken link

Signed-off-by: Tierney Cyren <hello@bnb.im>

Author: bnb

doc/README.md

@@ -319,7 +319,7 @@ belongs to a module or a class.
 [Use US spelling]: https://docs.microsoft.com/en-us/style-guide/word-choice/use-us-spelling-avoid-non-english-words
 [Use serial commas]: https://docs.microsoft.com/en-us/style-guide/punctuation/commas
 [`remark-preset-lint-node`]: https://github.com/nodejs/remark-preset-lint-node
-[doctools README]: ../../tools/doc/README.md
+[doctools README]: ../tools/doc/README.md
 [info string]: https://github.github.com/gfm/#info-string
 [language]: https://github.com/highlightjs/highlight.js/blob/HEAD/SUPPORTED_LANGUAGES.md
 [plugin]: https://editorconfig.org/#download