Correct filenames of Twig extensions

Author: TxHawks

README.md

@@ -148,7 +148,7 @@ The requirements for using filters with Pattern Lab:
 * The filter **must** set the variable `$filter`
 * Only one filter per file (_e.g. can only set `$filter` once per file_)
 
-An example function called `rot13.filter.twig` in `source/_twig-components/filters`:
+An example function called `rot13.filter.php` in `source/_twig-components/filters`:
 
 ```php
 <?php
@@ -175,7 +175,7 @@ The requirements for using functions with Pattern Lab:
 * The function **must** set the variable `$function`
 * Only one function per file (_e.g. can only set `$function` once per file_)
 
-An example function called `boo.function.twig` in `source/_twig-components/functions`:
+An example function called `boo.function.php` in `source/_twig-components/functions`:
 
 ```php
 <?php
@@ -202,7 +202,7 @@ The requirements for using tests with Pattern Lab:
 * The test **must** set the variable `$test`
 * Only one test per file (_e.g. can only set `$test` once per file_)
 
-An example of a simple test called `red.test.twig` in `source/_twig-components/tests`:
+An example of a simple test called `red.test.php` in `source/_twig-components/tests`:
 
 ```php
 <?php
@@ -254,7 +254,7 @@ Tags are the most complicated extension to set-up with Pattern Lab. Three steps
 
 Pattern Lab takes care of the registering for you based on the file name.
 
-An example of a simple tag called `setdupe.tag.twig` in `source/_twig-components/tags` that mimics the default `set` tag. Please note all of the locations where class names incorporate the filename, `setdupe`.
+An example of a simple tag called `setdupe.tag.php` in `source/_twig-components/tags` that mimics the default `set` tag. Please note all of the locations where class names incorporate the filename, `setdupe`.
 
 ```php
 <?php
@@ -328,11 +328,11 @@ You can modify the default date and interval formats for Twig by editing the `tw
 
 To disable extensions that you're no longer using simply add an underscore to the beginning of a filename and then re-generate your site. For example, the enabled rot13 filter:
 
-    source/_twig-components/filters/rot13.filter.twig
+    source/_twig-components/filters/rot13.filter.php
 
 And the disabled rot13 filter:
 
-    source/_twig-components/filters/_rot13.filter.twig
+    source/_twig-components/filters/_rot13.filter.php
 
 Then re-generate your Pattern Lab site with: