Broken link to Contributing doc #1612
Description
Hi, first time reporting an issue here 👋🏼
I was trying to find the Contributing guideline document. The repo links it to https://bundler.io/doc/readme.html but I get a 404. I tried to find where the document lives now to update it with the correct link but couldn't find it. I also couldn't find it in the sitemap.
There are a few places with the broken link: https://github.com/search?q=repo%3Arubygems%2Fbundler-site%20doc%2Freadme.html&type=code