User guide: rephrase "in order to use this feature" a little (#58)

Author: Frenzie

user_guide/en.html

@@ -3006,7 +3006,7 @@
     <p>
     <b>OCR (Optical Character Recognition)</b> is the process of extracting text from images. In KOReader context, it is generally used for extracting text from scanned book pages in PDF files. KOReader relies on <a href="https://github.com/tesseract-ocr/tessdoc">Tesseract Open Source OCR Engine</a> for this task.</p>
 
-    <p>In order to use this feature you need to:</p>
+    <p>To use this feature you need to:</p>
     <ol>
         <li>Install <span class=external>Tesseract</span> language data to your KOReader</li>
         <li>Add newly installed languages to koreader/defaults.lua configuration file