Update nim.rb

[commandline-be]

added most recent version 2.2.0

If you’re adding a new scraper, please ensure that you have:

• [ ] Tested the scraper on a local copy of DevDocs
• [x] Ensured that the docs are styled similarly to other docs on DevDocs
• [ ] Added these files to the public/icons/your_scraper_name/ directory:
  • [ ] 16.png: a 16×16 pixel icon for the doc
  • [ ] 16@2x.png: a 32×32 pixel icon for the doc
  • [ ] SOURCE: A text file containing the URL to the page the image can be found on or the URL of the original image itself

If you're updating existing documentation to its latest version, please ensure that you have:

• [x] Updated the versions and releases in the scraper file
• [x ] Ensured the license is up-to-date
• [ ] Ensured the icons and the SOURCE file in public/icons/your_scraper_name/ are up-to-date if the documentation has a custom icon
• [x ] Ensured self.links contains up-to-date urls if self.links is defined
• [ ] Tested the changes locally to ensure:
  • The scraper still works without errors
  • The scraped documentation still looks consistent with the rest of DevDocs
  • The categorization of entries is still good