Bump unicode-display_width from 1.4.1 to 1.5.0 in /docs

Bumps [unicode-display_width](https://github.com/janlelis/unicode-display_width) from 1.4.1 to 1.5.0.
- [Release notes](https://github.com/janlelis/unicode-display_width/releases)
- [Changelog](https://github.com/janlelis/unicode-display_width/blob/master/CHANGELOG.md)
- [Commits](https://github.com/janlelis/unicode-display_width/compare/v1.4.1...v1.5.0

)

Signed-off-by: dependabot[bot] <support@dependabot.com>

docs/Gemfile.lock

@@ -248,7 +248,7 @@ GEM
       ethon (>= 0.9.0)
     tzinfo (1.2.5)
       thread_safe (~> 0.1)
-    unicode-display_width (1.4.1)
+    unicode-display_width (1.5.0)
     yell (2.0.7)
 
 PLATFORMS