reference: Add keywords in group block.

alias, broadcast_signal, inherit, limits, max, min, script, and their
children keywords are added.

The descriptions refer the following website.
https://developer.tizen.org/dev-guide/2.3.1/org.tizen.guides/html/native/ui/edc_part_block_n.htm

data/reference/reference.src

@@ -18,6 +18,12 @@ collections { "The <hilight>collections</hilight> represents a theme.</br>The <h
    }
 
    group { "The <hilight>group</hilight> represents a widget style.</br>The <hilight>group</hilight> block contains parts and programs that compose a widget style.";
+      alias { "Additional name to be used as an identifier. Defining multiple aliases is supported.";
+      }
+
+      broadcast_signal { "Signal gets automatically broadcasted to all sub group parts. Default is "on".";
+      }
+
       data { "The <hilight>data</hilight> block is used to pass arbitrary parameters from the theme to the application.";
          item { "Defines a new parameter, the value is the string specified next to it.";
          }
@@ -43,6 +49,22 @@ collections { "The <hilight>collections</hilight> represents a theme.</br>The <h
          }
       }
 
+      inherit { "Parent group name for inheritance.</br>Group inherit is used to inherit any predefined group and change some property which belongs to part, description, items or program. The child group has the same properties as its parent group.</br>If you specify the type again in an inherited part, it causes an error.";
+      }
+
+      limits { "This block is used to trigger signals when the Edje object is resized.";
+         horizontal { "This sends a signal limit,name,over when the object is resized and passes the limit by growing over it.</br>When the object's size is reduced below the limit, signal limit,name,below is sent.</br>This limit is applied on the y axis and is given in pixels.";
+         }
+         vertical { "This sends a signal limit,name,over when the object is resized and passes the limit by growing over it.</br>When the object's size is reduced below the limit, signal limit,name,below is sent.</br>This limit is applied on the x axis and is given in pixels.";
+         }
+      }
+
+      max { "The maximum size for the container defined by the totality of the parts.";
+      }
+
+      min { "The minimum size for the container defined by the composition of the parts.";
+      }
+
       parts { "The <hilight>parts</hilight> represents visual elements.</br>The <hilight>parts</hilight> block contains a list of parts that describes a basic design element.";
          part { "The <hilight>part</hilight> represents a basic design element such as an image, rectangle or text.</br>The <hilight>part</hilight> block contains a list of descriptions that defines a state of the element.";
             desc { "The <hilight>desc</hilight> defines a state of a part.</br>The <hilight>desc</hilight> block contains properties of a part such as a size, position, color, image and text.";
@@ -75,6 +97,9 @@ collections { "The <hilight>collections</hilight> represents a theme.</br>The <h
          }
       }
 
+      script { "The <hilight>script</hilight> block is used to inject embryo scripts to a given Edje theme and it functions in two modalities. When it is included inside a program block, the script is executed every time the program is run, on the other hand, when included directly into a group, part, or description block, it is executed once at the load time, in the load order.";
+      }
+
       sounds { "The <hilight>sounds</hilight> block contains a list of one or more sound samples and tone items.";
          sample { "The <hilight>sample</hilight> block defines the sound sample.";
             name { "Used to include each sound file. Valid types are RAW, COMP, LOSSY, and AS_IS.";