[Update] Documentation for sniff WordPress.Files.FilesName

WordPress/Docs/Files/FileNameStandard.xml

@@ -0,0 +1,63 @@
+<?xml version="1.0"?>
+<documentation xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:noNamespaceSchemaLocation="https://phpcsstandards.github.io/PHPCSDevTools/phpcsdocs.xsd" 
+    title="File Name"
+    >
+    <standard>
+    <![CDATA[
+    Filenames should be all lowercase with hyphens separating words.
+    ]]>
+    </standard>
+    <code_comparison>
+        <code title="Valid: Lowercase and `-` separators.">
+        <![CDATA[
+taxonomy<em>-</em>my<em>-</em>term.inc
+<em>some</em>-<em>file</em>.inc
+other<em>-</em>punctuation.inc
+        ]]>
+        </code>
+        <code title="Invalid: Other punctuation or mixed case.">
+        <![CDATA[
+taxonomy-my<em>_</em>term.inc
+<em>Some</em>-<em>File</em>.inc
+other<em>+</em>punctuation<em>#</em>.inc
+        ]]>
+        </code>
+    </code_comparison>
+    <standard>
+    <![CDATA[
+    Class file names should be based on the class name with `class-` prepended.
+    ]]>
+    </standard>
+    <code_comparison>
+        <code title="Valid: File name matches prefix and class.">
+        <![CDATA[
+<em>class</em>-<em>bulk-updater</em>.php
+        ]]>
+        </code>
+        <code title="Invalid: File name missing prefix or class.">
+        <![CDATA[
+class<em>.</em>bulk-updater.php
+<em>bulk-updater</em>.php
+bulk-updater<em>-class</em>.php
+        ]]>
+        </code>
+    </code_comparison>
+    <standard>
+    <![CDATA[
+    Non-class files in the directory `wp-includes` with a "@subpackage Template" tag should use the `-template` suffix.
+    ]]>
+    </standard>
+    <code_comparison>
+        <code title="Valid: File name with proper suffix.">
+        <![CDATA[
+general<em>-template</em>.php
+        ]]>
+        </code>
+        <code title="Invalid: File name missing prefix/suffix.">
+        <![CDATA[
+<em>general</em>.php
+        ]]>
+        </code>
+    </code_comparison>
+</documentation>