Update rubybench_runner guide

Author: OsamaSayegh

app/helpers/repos_helper.rb

@@ -5,4 +5,8 @@ def show_gem_tip
     @benchmark &&
     @benchmark.category !~ /^discourse_/
   end
+
+  def script_name
+    @benchmark.script_url.match(/\/([^\/]+)$/)[1]
+  end
 end

app/views/repos/_script.html.haml

@@ -1,7 +1,6 @@
 - if script_url = benchmark.script_url
   - if show_gem_tip
-    %h4.l-align-center
-      != t('repos.run_locally_tip', path: run_locally_path)
+    != t('repos.run_locally_tip', path: run_locally_path, script: script_name)
   %h2.l-align-center
     = t('repos.script_title', graph_name: benchmark.category.humanize)
 

config/locales/en.yml

@@ -30,7 +30,11 @@ en:
       "%{category}" does not have any results. Please select another
       Benchmark Type.
     view_github: View on Github
-    run_locally_tip: You can run this benchmark locally using the <code>rubybench_runner</code> gem. More details <a href="%{path}">here</a>.
+    run_locally_tip: |
+      <p>You can run this benchmark locally using the <code>rubybench_runner</code> gem:</p>
+      <pre>gem install rubybench_runner
+      rubybench_runner run rails/%{script}</pre>
+      More details <a href="%{path}">here</a>.
 
     index:
       commits_benchmark: Commits Benchmarks
@@ -92,7 +96,10 @@ en:
           </li>
           <li>Pick one of the <a href="https://rubybench.org/rails/rails/commits">available rails benchmarks</a> and copy the GitHub link of the script (it's the "View on Github" button).</li>
           <li>Run:
-            <pre>rubybench_runner run rails &lt;script_url&gt; &lt;path_to_rails_clone&gt;</pre>
+            <pre>rubybench_runner run rails/&lt;script_name&gt; --rails=/path/to/rails</pre>
+            You can get <code>script_name</code> from the page of the benchmark that you want to run at rubybench.org.
+            <br>
+            If you have Rails cloned in your home directory, you can omit the <code>--rails</code> flag.
           </li>
           <li>If the benchmark requires a database server, then you need to specify the <code>--db</code> option. Run <code>rubybench_runner --help</code> for details.</li>
         </ul>