Avoid processing all html multiple times, instead skip to one version

The previous script run commands `ag` commands on rspec-github.io and
not the source/lib/version folder. It means we are doing extra work
everytime we generate documentation.

With this change we reduce the scope of files that can be processed but
also the command is much faster.

Author: benoittgt

Rakefile

@@ -65,10 +65,11 @@ task :update_docs, [:version, :branch, :website_path] do |t, args|
   args.with_defaults(:website_path => "../rspec.github.io")
   run_command "git checkout #{args[:branch]} && git pull --rebase"
   each_project :except => (UnDocumentedProjects + SemverUnlinkedProjects) do |project|
+    doc_destination_path = "#{args[:website_path]}/source/documentation/#{args[:version]}/#{project}/"
     cmd = "bundle install && \
            RUBYOPT='-I#{args[:website_path]}/lib' bundle exec yard \
                             --yardopts .yardopts \
-                            --output-dir #{args[:website_path]}/source/documentation/#{args[:version]}/#{project}/"
+                            --output-dir #{doc_destination_path}"
     puts cmd
     Bundler.unbundled_system(cmd)
     in_place =
@@ -78,9 +79,9 @@ task :update_docs, [:version, :branch, :website_path] do |t, args|
         "-i''"
       end
 
-    Bundler.unbundled_system %Q{pushd #{args[:website_path]}; ag -l src=\\"\\\(?:..\/\\\)*js | xargs -I{} sed #{in_place} 's/src="\\\(..\\\/\\\)*js/src="\\\/documentation\\\/#{args[:version]}\\\/#{project}\\\/js/' {}; popd}
-    Bundler.unbundled_system %Q{pushd #{args[:website_path]}; ag -l href=\\"\\\(?:..\/\\\)*css | xargs -I{} sed #{in_place} 's/href="\\\(..\\\/\\\)*css/href="\\\/documentation\\\/#{args[:version]}\\\/#{project}\\\/css/' {}; popd}
-    Bundler.unbundled_system %Q{pushd #{args[:website_path]}; ag --html -l | xargs -I{} sed #{in_place} /^[[:space:]]*$/d {}; popd}
+    Bundler.unbundled_system %Q{ag -l src=\\"\\\(?:..\/\\\)*js #{doc_destination_path} | xargs -I{} sed #{in_place} 's/src="\\\(..\\\/\\\)*js/src="\\\/documentation\\\/#{args[:version]}\\\/#{project}\\\/js/' {}}
+    Bundler.unbundled_system %Q{ag -l href=\\"\\\(?:..\/\\\)*css #{doc_destination_path} | xargs -I{} sed #{in_place} 's/href="\\\(..\\\/\\\)*css/href="\\\/documentation\\\/#{args[:version]}\\\/#{project}\\\/css/' {}}
+    Bundler.unbundled_system %Q{ag --html -l . #{doc_destination_path} | xargs -I{} sed #{in_place} /^[[:space:]]*$/d {}}
   end
 end