Formats: Remove display & related method (#2776)

Format should not be responsible for sending HTTP response.

docs/08_Format_API/02_FormatInterface.md

@@ -14,14 +14,6 @@ Find a [template](#template) at the end of this file
 
 # Functions
 
-## The `display` function
-
-The `display` function shows the contents to the user and must return the object instance.
-
-```PHP
-display(): self
-```
-
 ## The `stringify` function
 
 The `stringify` function returns the items received by [`setItems`](#the-setitem-function) as string.
@@ -109,12 +101,6 @@ class MyTypeFormat implements FormatInterface {
         return ''; // Return items as string
     }
 
-    public function display(){
-        // Implement your code here
-        echo $this->stringify();
-        return $this;
-    }
-
     public function setItems(array $items){
         $this->items = $items;
         return $this;

docs/08_Format_API/03_FormatAbstract.md

@@ -1,27 +1,9 @@
 The `FormatAbstract` class implements the [`FormatInterface`](../08_Format_API/02_FormatInterface.md) interface with basic functional behavior and adds common helper functions for new formats:
 
-* [setContentType](#the-setcontenttype-function)
-* [callContentType](#the-callcontenttype-function)
 * [sanitizeHtml](#the-sanitizehtml-function)
 
 # Functions
 
-## The `setContentType` function
-
-The `setContentType` function receives a string defining the content type for the HTML header and must return the object instance.
-
-```PHP
-setContentType(string): self
-```
-
-## The `callContentType` function
-
-The `callContentType` function applies the content type to the header data and must return the object instance.
-
-```PHP
-callContentType(): self
-```
-
 ## The `sanitizeHtml` function
 
 The `sanitizeHtml` function receives an HTML formatted string and returns the string with disabled `<script>`, `<iframe>` and `<link>` tags.