[Update] Documentation for sniff WordPress.Files.FilesName

WordPress/Docs/Files/FileNameStandard.xml

@@ -0,0 +1,86 @@
+<?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 Standards"
+    >
+    <standard>
+    <![CDATA[
+File name must not be a mimetype sublevel only file names, such as `plain.php`.
+    ]]>
+    </standard>
+    <code_comparison>
+        <code title="Valid: Is not a mimetype only file name.">
+        <![CDATA[
+<em>taxonomy-term</em>.inc
+<em>class-test-sample</em>.php
+<em>other-punctuation</em>.inc
+        ]]>
+        </code>
+        <code title="Invalid: Is a mimetype only file name.">
+        <![CDATA[
+<em>text-plain</em>.php
+<em>html</em>.inc
+<em>richtext</em>.php
+        ]]>
+        </code>
+    </code_comparison>
+    <standard>
+    <![CDATA[
+Filenames should be all lowercase with hyphens separating words. If `$is_theme` property is set to `true` certain theme specific exceptions are made for underscores.
+    ]]>
+    </standard>
+    <code_comparison>
+        <code title="Valid: Lowercase and `-` separators.">
+        <![CDATA[
+taxonomy<em>-</em>my<em>-</em>term.inc
+<em>s</em>ome<em>f</em>ile.inc
+<em>class</em>-testsample.inc
+other<em>-</em>punctuation.inc
+        ]]>
+        </code>
+        <code title="Invalid: Other punctuation or mixed case.">
+        <![CDATA[
+taxonomy-my<em>_</em>term.inc
+<em>S</em>ome<em>F</em>ile.inc
+<em>testsample</em>-Unit2.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-bulkupdater</em>.php
+        ]]>
+        </code>
+        <code title="Invalid: File name missing prefix or class.">
+        <![CDATA[
+<em>class.</em>bulk-updater.php
+<em>bulkupdater-class</em>.php
+class-<em>CustomFormatter</em>.php
+        ]]>
+        </code>
+    </code_comparison>
+    <standard>
+    <![CDATA[
+   Files in `wp-includes` containing template tags should end in `-template`.
+    ]]>
+    </standard>
+    <code_comparison>
+        <code title="Valid: File name with proper prefix/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>