[manual] Upper-case A in lookAhead

Author: toddself

doc/manual.html

@@ -3242,7 +3242,7 @@ <h2>Writing CodeMirror Modes</h2>
       <dd>Get the string between the start of the current token and
       the current stream position.</dd>
 
-      <dt><code><strong>lookahead</strong>(n: number) → ?string</code></dt>
+      <dt><code><strong>lookAhead</strong>(n: number) → ?string</code></dt>
       <dd>Get the line <code>n</code> (&gt;0) lines after the current
       one, in order to scan ahead across line boundaries. Note that
       you want to do this carefully, since looking far ahead will make