Add note on Exclamation mark ! logical operator (#220)

Reference #113

manual/php.md

@@ -45,6 +45,8 @@ For all control structures there is a space between the keyword and an opening p
 
 For all all control structures, such as `if`, `else`, `do`, `for`, `foreach`, `try`, `catch`, `switch` and `while`, both the keyword starts a newline and the opening and closing braces are each put on a new line.
 
+Exclamation mark `!`, the logical operator `not` used in a condition, should not have spaces before or after the exclamation mark as shown in the examples.
+
 #### An _if-else_ Example
 
 ```php
@@ -55,11 +57,14 @@ if ($test)
 
 // Comments can go here.
 // Note that "elseif" as one word is used.
-
 elseif ($test === false)
 {
 	echo 'Really false';
 }
+elseif (!$condition)
+{
+	echo 'Not Condition';
+}
 else
 {
 	echo 'A white lie';