Bump rubyzip from 1.2.2 to 2.0.0 in /docs (#759)

Bumps [rubyzip](https://github.com/rubyzip/rubyzip) from 1.2.2 to 2.0.0.
- [Release notes](https://github.com/rubyzip/rubyzip/releases)
- [Changelog](https://github.com/rubyzip/rubyzip/blob/master/Changelog.md)
- [Commits](https://github.com/rubyzip/rubyzip/compare/v1.2.2...v2.0.0)

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

docs/Gemfile.lock

@@ -219,7 +219,7 @@ GEM
     ruby-enum (0.7.2)
       i18n
     ruby_dep (1.5.0)
-    rubyzip (1.2.2)
+    rubyzip (2.0.0)
     safe_yaml (1.0.4)
     sass (3.7.2)
       sass-listen (~> 4.0.0)