Add section settings documentation

Author: ivanlanin

README.md

@@ -34,8 +34,10 @@ the following lines to your ``composer.json``.
 ### Table of contents
 
 1. [Basic usage](#basic-usage)
+    * [Measurement units](#measurement-units)
 2. [Sections](#sections)
-    * [Change Section Page Numbering](#sections-page-numbering)
+    * [Section settings](#section-settings)
+    * [Section page numbering](#section-page-numbering)
 3. [Tables](#tables)
     * [Cell Style](#tables-cell-style)
 4. [Images](#images)
@@ -75,6 +77,7 @@ $objWriter = PHPWord_IOFactory::createWriter($PHPWord, 'Word2007');
 $objWriter->save('helloWorld.docx');
 ```
 
+<a name="measurement-units"></a>
 ##### Measurement units
 
 The base length unit in Open Office XML is twip. Twip means "TWentieth of an Inch Point", i.e. 1 twip = 1/1440 inch.
@@ -98,8 +101,51 @@ $sectionStyle->setMarginRight(PHPWord_Shared_Font::centimeterSizeToTwips(2));
 <a name="sections"></a>
 #### Sections
 
-<a name="sections-page-numbering"></a>
-##### Change Section Page Numbering
+Every visible element in word is placed inside of a section. To create a section, use the following code:
+
+```php
+$section = $PHPWord->createSection($sectionSettings);
+```
+The `$sectionSettings` is an optional associative array that sets the section. Example:
+
+```php
+$sectionSettings = array(
+    'orientation' => 'landscape',
+    'marginTop' => 600,
+    'colsNum' => 2,
+);
+```
+<a name="section-settings"></a>
+##### Section settings
+
+Below are the available settings for section:
+
+* `orientation` Page orientation, i.e. 'portrait' (default) or 'landscape'
+* `marginTop` Page margin top in twips
+* `marginLeft` Page margin left in twips
+* `marginRight` Page margin right in twips
+* `marginBottom` Page margin bottom in twips
+* `borderTopSize` Border top size in twips
+* `borderTopColor` Border top color
+* `borderLeftSize` Border left size in twips
+* `borderLeftColor` Border left color
+* `borderRightSize` Border right size in twips
+* `borderRightColor` Border right color
+* `borderBottomSize` Border bottom size in twips
+* `borderBottomColor` Border bottom color
+* `headerHeight` Spacing to top of header
+* `footerHeight` Spacing to bottom of footer
+* `colsNum` Number of columns
+* `colsSpace` Spacing between columns
+* `breakType` Section break type (nextPage, nextColumn, continuous, evenPage, oddPage)
+
+The following two settings are automatically set by the use of the `orientation` setting. You can alter them but that's not recommended.
+
+* `pageSizeW` Page width in twips
+* `pageSizeH` Page height in twips
+
+<a name="section-page-numbering"></a>
+##### Section page numbering
 
 You can change a section page numbering.