Cleanup/Consistency: Replace double quotes to single ones

Author: pH-7

README.md

@@ -67,10 +67,10 @@ Http::getProtocol()
 use PH7\PhpHttpResponseHeader\Header;
 
 // Send "Content-Type: application/json" header to the browser
-Http::setContentType("application/json");
+Http::setContentType('application/json');
 
 // Send "Content-type: text/xml" to the browser
-Http::setContentType("text/xml");
+Http::setContentType('text/xml');
 ```
 
 

src/Http.php

@@ -79,11 +79,11 @@ class Http
 
 
     /**
-     * Give the HTTP status code name (e.g. "204 No Content").
+     * Give the HTTP status code name (e.g. '204 No Content').
      *
      * @param int $status The "code" for the HTTP status.
      *
-     * @return string|bool $status The "HTTP status code" if found, FALSE otherwise.
+     * @return string|bool $status The correct HTTP status code if found, FALSE otherwise.
      */
     public static function getStatusCode(int $status): string|bool
     {
@@ -137,7 +137,7 @@ public static function setHeadersByCode(int $code = StatusCode::OK): void
     /**
      * Set a HTTP Content Type.
      *
-     * @param string $type The content type value. e.g., "text/xml".
+     * @param string $type The content type value. e.g. 'text/xml'
      *
      * @throws Exception
      */