Skip tests tagged as document: false on doc gen

When running the below command to re-generate API docs:
RAILS_ENV=test rake docs:generate
it will execute every single rspec test under 'spec/acceptance/**/*_spec.rb'.
It *even* executes the tests that are explicitly marked as:
document: false
With this new rake task, only the rspec tests that contribute to the generation of
API documentation will be executed:
RAILS_ENV=test rake docs:generate:skip_undocumenting

Aside: For our team, this reduced the amount of tests being executed during
docs generation down from 195 to 37.

Author: stwr667

lib/tasks/docs.rake

@@ -11,3 +11,9 @@ RSpec::Core::RakeTask.new('docs:generate:ordered') do |t|
   t.pattern = 'spec/acceptance/**/*_spec.rb'
   t.rspec_opts = ["--format RspecApiDocumentation::ApiFormatter", "--order defined"]
 end
+
+desc "Generate API request documentation from API specs, and skip tests that don't generate any docs"
+RSpec::Core::RakeTask.new('docs:generate:skip_undocumenting') do |t|
+  t.pattern = 'spec/acceptance/**/*_spec.rb'
+  t.rspec_opts = ["--format RspecApiDocumentation::ApiFormatter", "--tag ~@document:false"]
+end