docs: add webrick dependency
webrick needs to be installed for ruby versions >3, which should ease
local testing for someone running newer versions. This is compatible
with running on ruby 2.7.4, the version used on github pages.
Signed-off-by: Fabio Utzig <utzig@apache.org>
diff --git a/docs/Gemfile b/docs/Gemfile
index fd9a462..b88481b 100644
--- a/docs/Gemfile
+++ b/docs/Gemfile
@@ -22,3 +22,5 @@
gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]
gem "jemoji", "~> 0.12.0"
+
+gem "webrick", "~> 1.8"