Correct spelling from "givne" to "given".

Author: Primigenus

doc/manual.html

@@ -620,7 +620,7 @@ <h2 id="api">Programming API</h2>
       <dd>Set the selection range. <code>anchor</code>
       and <code>head</code> should be <code>{line, ch}</code>
       objects. <code>head</code> defaults to <code>anchor</code> when
-      not givne.</dd>
+      not given.</dd>
 
       <dt id="getLine"><code>getLine(n) → string</code></dt>
       <dd>Get the content of line <code>n</code>.</dd>