Update documentation with number format

Author: adrilo

docs/_pages/documentation.md

@@ -116,18 +116,19 @@ $reader->setShouldPreserveEmptyRows(true);
 
 For fonts and alignments, {{ site.spout_html }} does not support all the possible formatting options yet. But you can find the most important ones:
 
-| Category  | Property       | API
-|:----------|:---------------|:--------------------------------------
-| Font      | Bold           | `StyleBuilder::setFontBold()`
-|           | Italic         | `StyleBuilder::setFontItalic()`
-|           | Underline      | `StyleBuilder::setFontUnderline()`
-|           | Strikethrough  | `StyleBuilder::setFontStrikethrough()`
-|           | Font name      | `StyleBuilder::setFontName('Arial')`
-|           | Font size      | `StyleBuilder::setFontSize(14)`
-|           | Font color     | `StyleBuilder::setFontColor(Color::BLUE)`<br>`StyleBuilder::setFontColor(Color::rgb(0, 128, 255))`
-| Alignment | Cell alignment | `StyleBuilder::setCellAlignment(CellAlignment::CENTER)`
-|           | Wrap text      | `StyleBuilder::setShouldWrapText(true)`
-
+| Category             | Property       | API
+|:---------------------|:---------------|:--------------------------------------
+| Font                 | Bold           | `StyleBuilder::setFontBold()`
+|                      | Italic         | `StyleBuilder::setFontItalic()`
+|                      | Underline      | `StyleBuilder::setFontUnderline()`
+|                      | Strikethrough  | `StyleBuilder::setFontStrikethrough()`
+|                      | Font name      | `StyleBuilder::setFontName('Arial')`
+|                      | Font size      | `StyleBuilder::setFontSize(14)`
+|                      | Font color     | `StyleBuilder::setFontColor(Color::BLUE)`<br>`StyleBuilder::setFontColor(Color::rgb(0, 128, 255))`
+| Alignment            | Cell alignment | `StyleBuilder::setCellAlignment(CellAlignment::CENTER)`
+|                      | Wrap text      | `StyleBuilder::setShouldWrapText(true)`
+| Format _(XLSX only)_ | Number format  | `StyleBuilder::setFormat('0.000')`
+|                      | Date format    | `StyleBuilder::setFormat('m/d/yy h:mm')`
 
 ### Styling rows