Merge pull request #4361 from duojet2ez/update-contributing-doc

removed '?might work' from usaco.guide/general/contributing

Author: bqi343

content/1_General/Contributing.mdx

@@ -45,7 +45,7 @@ is useful if you need to use Tailwind CSS classes, which don't work with
    - Install [node.js](https://nodejs.org/en/)
      - [Gatsby docs](https://www.gatsbyjs.org/tutorial/part-zero/#install-nodejs-for-your-appropriate-operating-system)
    - Install [yarn](https://classic.yarnpkg.com/en/)
-     - `npm install -g yarn`? might work
+     - `npm install -g yarn`
 2. Clone repo
    - Via command line:
      `git clone https://github.com/cpinitiative/usaco-guide.git`