remove double negative from markdown.md heading

markdown.html

@@ -433,7 +433,7 @@ for the given page URL.</p>
 <pre><code>    &lt;span style=&quot;font-family: monospace;&quot;&gt;Use of monospaced font is one option&lt;/span&gt;</code></pre>
 <p>Or better and easier still, use an inline markdown code block:</p>
 <pre><code>    `inline markdown code block is easier and much better`</code></pre>
-<h2 id="please-do-not-use-code-blocks-that-are-not-indented">Please do NOT use code blocks that are NOT indented</h2>
+<h2 id="please-do-not-use-unindented-code-blocks">Please do NOT use unindented code blocks</h2>
 <p>Please do <strong>NOT</strong> start code blocks at the left-hand edge.</p>
 <pre><code>```
 This code block                                               &lt;=== no thank you

markdown.md

@@ -113,7 +113,7 @@ Or better and easier still, use an inline markdown code block:
 ```
 
 
-## Please do NOT use code blocks that are NOT indented
+## Please do NOT use unindented code blocks
 
 Please do **NOT** start code blocks at the left-hand edge.