Add Dash documentation tool to all language versions

[Kapeli]

Summary

This PR adds Dash as a documentation resource across multiple language versions of the Ruby documentation pages. Dash is a popular macOS offline API documentation browser that supports Ruby.

Changes

Added Dash to 6 language versions that were missing it:

• English (en): Added in Community Documentation section alongside DevDocs
• Korean (ko): Added in Community Documentation section alongside DevDocs
• Traditional Chinese (zh_tw): Added in Community Documentation section alongside DevDocs
• German (de): Added in Reference Documentation section
• French (fr): Added in Reference Documentation section
• Russian (ru): Added in Editors and IDEs section under macOS

Notes

Ten other language versions (Bulgarian, Spanish, Indonesian, Italian, Japanese, Polish, Portuguese, Turkish, Vietnamese, Simplified Chinese) already had Dash mentioned in their Editors/IDEs sections.

[st0012]

What Dash features require purchase and what’s free?

[Kapeli]

The only feature that remains free is Dash's ability to download and generate docs for offline use.

Dash has a 30-day free trial, after which it continues to function fully, except that it displays pages after an 8-second delay in its internal browser, which makes navigating/browsing the docs within Dash quite bothersome. Users would then have to purchase Dash, or navigate the docs using an external browser.

Do you allow only free tools / resources in this listing? If that's the case, I completely understand and respect that decision. I don't think Dash would be a good fit.