Documentation: Update Beginner's Tutorial to use "MyVolume.hc" instead of "My Volume" for file container name in order to avoid confusion about nature of file nature for beginners who expect a file to always have an extension (cf https://github.com/veracrypt/VeraCrypt/issues/663) Update screenshots to reflect changes in VeraCrypt UI

doc/html/Beginner's Tutorial.html

@@ -71,8 +71,8 @@ <h4>STEP 6:</h4>
 <p><img src="Beginner's Tutorial_Image_005.jpg" alt="" width="720" height="452"><br>
 <br>
 In this tutorial, we will create our VeraCrypt volume in the folder F<em>:\Data\ </em>
-and the filename of the volume (container) will be <em>My Volume </em>(as can be seen in the screenshot above). You may, of course, choose any other filename and location you like (for example, on a USB memory stick). Note that the file
-<em>My Volume </em>does not exist yet &ndash; VeraCrypt will create it.</p>
+and the filename of the volume (container) will be <em>MyVolume.hc </em>(as can be seen in the screenshot above). You may, of course, choose any other filename and location you like (for example, on a USB memory stick). Note that the file
+<em>MyVolume.hc </em>does not exist yet &ndash; VeraCrypt will create it.</p>
 <p>IMPORTANT: Note that VeraCrypt will <em>not </em>encrypt any existing files (when creating a VeraCrypt file container). If you select an existing file in this step, it will be overwritten and replaced by the newly created volume (so the overwritten file
  will be <em>lost</em>, <em>not </em>encrypted). You will be able to encrypt existing files (later on) by moving them to the VeraCrypt volume that we are creating now.*</p>
 <p>Select the desired path (where you wish the container to be created) in the file selector. Type the desired container file name in the
@@ -116,7 +116,7 @@ <h4>STEP 11:</h4>
 <br>
 Click <strong>Format</strong>.<br>
 <br>
-Volume creation should begin. VeraCrypt will now create a file called <em>My Volume
+Volume creation should begin. VeraCrypt will now create a file called <em>MyVolume.hc
 </em>in the folder F<em>:\Data\ </em>(as we specified in Step 6). This file will be a VeraCrypt container (it will contain the encrypted VeraCrypt volume). Depending on the size of the volume, the volume creation may take a long time. After it finishes, the
  following dialog box will appear:<br>
 <br>