screenshot-page: standardize on double-quote attrs

screenshot-page.html

@@ -29,33 +29,33 @@
         <h3>Form elements</h3>
         <form>
           <div>
-            <label for='email'>Email</label>
+            <label for="email">Email</label>
-            <input type='email' name='email' id='email' placeholder='john.doe@gmail.com'>
+            <input type="email" name="email" id="email" placeholder="john.doe@gmail.com">
           </div>
 
           <div>
-            <label for='id'>User id (read only)</label>
+            <label for="id">User id (read only)</label>
-            <input readonly name='id' id='id' value='04D6H89Z'>
+            <input readonly name="id" id="id" value="04D6H89Z">
           </div>
 
           <div>
-            <label for='disabled'>Random disabled input</label>
+            <label for="disabled">Random disabled input</label>
-            <input disabled name='disabled' id='disabled' placeholder='Because why not?'>
+            <input disabled name="disabled" id="disabled" placeholder="Because why not?">
           </div>
 
           <div>
-            <label for='about'>About me</label>
+            <label for="about">About me</label>
-            <textarea name='about' id='about' placeholder='I am a textarea...'></textarea>
+            <textarea name="about" id="about" placeholder="I am a textarea..."></textarea>
           </div>
 
           <div>
-            <input type='checkbox' name='remember' id='remember'>
+            <input type="checkbox" name="remember" id="remember">
-            <label for='remember'>Remember me</label>
+            <label for="remember">Remember me</label>
           </div>
 
           <div>
             <label>
-              <input type='checkbox' name='in-label' id='in-label' checked>
+              <input type="checkbox" name="in-label" id="in-label" checked>
               Is this checkbox inside a <code>&lt;label&gt;</code> element?
             </label>
           </div>
@@ -65,29 +65,29 @@
               <legend>Choose a cardinal direction:</legend>
 
               <div>
-                <input type='radio' id='north' name='direction' value='north' checked>
+                <input type="radio" id="north" name="direction" value="north" checked>
-                <label for='north'>North</label>
+                <label for="north">North</label>
               </div>
 
               <div>
-                <input type='radio' id='east' name='direction' value='east'>
+                <input type="radio" id="east" name="direction" value="east">
-                <label for='east'>East</label>
+                <label for="east">East</label>
               </div>
 
               <div>
-                <input type='radio' id='south' name='direction' value='south'>
+                <input type="radio" id="south" name="direction" value="south">
-                <label for='south'>South</label>
+                <label for="south">South</label>
               </div>
 
               <div>
-                <input type='radio' id='west' name='direction' value='west'>
+                <input type="radio" id="west" name="direction" value="west">
-                <label for='west'>West</label>
+                <label for="west">West</label>
               </div>
 
             </fieldset>
           </div>
 
-          <input type='submit'>
+          <input type="submit">
         </form>
 
         <h3>Code</h3>
@@ -99,7 +99,7 @@
 
         <h3>Other</h3>
         <p>Here's a horizontal rule and image because I don't know where else to put them.</p>
-        <img src='http://via.placeholder.com/408x287' alt='Example image'>
+        <img src="http://via.placeholder.com/408x287" alt="Example image">
         <hr>
 
         <p>And here's a nicely marked up table!</p>
@@ -136,7 +136,7 @@
         </blockquote>
         <p>
           Lorem ipsum dolor sit amet, consectetur adipiscing elit. Quisque dictum hendrerit velit, quis ullamcorper sem congue ac. Quisque id magna rhoncus, sodales massa vel, vestibulum elit. Duis ornare accumsan egestas. Proin maximus lacus interdum leo molestie convallis. Orci varius natoque penatibus et magnis dis parturient montes, nascetur ridiculus mus. Ut iaculis risus eu felis feugiat, eu mollis neque elementum. Donec interdum, nisl id dignissim iaculis, felis dui aliquet dui, non fermentum velit lectus ac quam. Class aptent taciti sociosqu ad litora torquent per conubia nostra, per inceptos himenaeos.
-          <strong>This is strong,</strong> this is normal, <b>this is just bold,</b> <em>and this is emphasized!</em> And heck, <a href='/'>here</a>'s a link.
+          <strong>This is strong,</strong> this is normal, <b>this is just bold,</b> <em>and this is emphasized!</em> And heck, <a href="/">here</a>'s a link.
         </p>
         <ul>
           <li>Unordered list item 1</li>