cleaner layout per tab (#1992)

lib/plugins/html/templates/url/coach/index.pug

@@ -30,7 +30,10 @@ mixin adviceInfo(name, perfectScore, node)
 - var advice = pageInfo.data.coach.run ? pageInfo.data.coach.run.advice : pageInfo.data.coach.pageSummary.advice;
 
 h2 Coach
-
+p.small
+  a(href='https://github.com/sitespeedio/coach') The coach
+  |  helps you find performance problems on your web page using web performance best practice rules. And gives you advice on accessibility and best practices.
+  
 script(type='text/javascript').
   function toggleRow(toggleElement) {
     var rows = toggleElement.nextSibling.getElementsByClassName("u-hideable");

lib/plugins/html/templates/url/iteration/index.pug

@@ -33,7 +33,6 @@ block content
   #tabSections
     section#summary-panel
        h2 Summary
-       p.small Summary of some of the most important metrics.
 
        .row
          .one-half.column

lib/plugins/html/templates/url/metrics/index.pug

@@ -3,9 +3,6 @@
 - var visualMetrics = browsertime.visualMetrics;
 - baseHelpURL = rootPath + 'help.html#';
 
-a
-h2 Metrics
-
 if options.browsertime.visualMetrics && visualMetrics
   a#visualmetrics
   h3 Visual Metrics