Add documentation for the sniff

Author: dingo-d

Universal/Docs/DeclareStatements/DeclareStatementsStyleStandard.xml

@@ -0,0 +1,53 @@
+<?xml version="1.0"?>
+<documentation xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:noNamespaceSchemaLocation="https://phpcsstandards.github.io/PHPCSDevTools/phpcsdocs.xsd"
+    title="Declare Statements Style"
+    >
+    <standard>
+    <![CDATA[
+        Declare statements should, by default, be written without curly braces/alternative syntax.
+    ]]>
+    </standard>
+    <code_comparison>
+        <code title="Valid: Declare statement written without curly braces.">
+        <![CDATA[
+declare(strict_types=1);
+        ]]>
+        </code>
+        <code title="Invalid: Declare statement written with curly braces.">
+        <![CDATA[
+declare(encoding='ISO-8859-1', ticks=1) {
+    // Code.
+}
+        ]]>
+        </code>
+        <code title="Invalid: Declare statement written using alternative syntax.">
+        <![CDATA[
+declare(encoding='ISO-8859-1', ticks=10):
+    declare(ticks=1):
+    // Code.
+    enddeclare;
+enddeclare;
+        ]]>
+        </code>
+    </code_comparison>
+    <standard>
+    <![CDATA[
+        strict_types declaration directive mustn't be written using curly braces, or with alternative syntax.
+    ]]>
+    </standard>
+    <code_comparison>
+        <code title="Valid: strict_types written without curly braces.">
+        <![CDATA[
+declare(strict_types=1);
+        ]]>
+        </code>
+        <code title="Invalid: strict_types written using alternative syntax/curly braces.">
+        <![CDATA[
+declare(strict_types=1, ticks=1) {
+   // Code.
+}
+        ]]>
+        </code>
+    </code_comparison>
+</documentation>