[Docs] Clarify the switch to canonifyurls = false as default

Quote from @spf13: "I also think it's the better default
and should continue to be the case going forward."

Also mention the use of `hugo config` to check the current value
of `canonifyurls`, thanks to suggestion by @bep.

Fixes #802

docs/content/extras/urls.md

@@ -32,20 +32,14 @@ Organization](/content/organization/) for more details.
 
 ## Canonicalization
 
-<!--
-By default, all relative URLs encountered in the input will be canonicalized
-using `baseurl`, so that a link `/css/foo.css` becomes
-`http://yoursite.example.com/css/foo.css`.
-
-By setting `canonifyurls` to `false` will prevent this canonicalization.
--->
 By default, all relative URLs encountered in the input are left unmodified,
-e.g. `/css/foo.css` would stay as `/css/foo.css`.
+e.g. `/css/foo.css` would stay as `/css/foo.css`,
+i.e. `canonifyurls` defaults to `false`.
 
 By setting `canonifyurls` to `true`, all relative URLs would instead
 be *canonicalized* using `baseurl`.  For example, assuming you have
 `baseurl = http://yoursite.example.com/` defined in the site-wide
-config.toml, the relative URL `/css/foo.css` would be turned into
+`config.toml`, the relative URL `/css/foo.css` would be turned into
 the absolute URL `http://yoursite.example.com/css/foo.css`.
 
 Benefits of canonicalization include fixing all URLs to be absolute, which may
@@ -56,46 +50,13 @@ Benefits of non-canonicalization include being able to have resource inclusion
 be scheme-relative, so that http vs https can be decided based on how this
 page was retrieved.
 
-### Caveat: Default of `canonifyurls` changed in v0.11
-
-<table class="table table-bordered">
-<thead>
-<tr>
-<th>Hugo Version</th>
-<th>Release Date</th>
-<th>Default</th>
-</tr>
-</thead>
+> Note: In the May 2014 release of Hugo v0.11, the default value of `canonifyurls` was switched from `true` to `false`, which we think is the better default and should continue to be the case going forward. So, please verify and adjust your website accordingly if you are upgrading from v0.10 or older versions.
 
-<tbody>
-<tr>
-<td>v0.9</td>
-<td>2013-11-15</td>
-<td><code>canonifyurls = true</code> <small>(non-configurable)</small></td>
-</tr>
+To find out the current value of `canonifyurls` for your website, you may use the handy `hugo config` command added in v0.13:
 
-<tr>
-<td>v0.10</td>
-<td>2014-03-01</td>
-<td><code>canonifyurls = true</code></td>
-</tr>
+    hugo config | grep -i canon
 
-<tr>
-<td>v0.11</td>
-<td>2014-05-29</td>
-<td><code>canonifyurls = false</code></td>
-</tr>
+Or, if you are on Windows and do not have `grep` installed:
 
-<tr>
-<td>v0.12</td>
-<td>2014-09-01</td>
-<td><code>canonifyurls = false</code></td>
-</tr>
+    hugo config | FINDSTR /I canon
 
-<tr>
-<td>v0.13-DEV</td>
-<td><small>in development</small></td>
-<td><code>canonifyurls = false</code> <small>(as of January 2015)</small></td>
-</tr>
-</tbody>
-</table>