_contents of the `theme/preprocess/README.md`_


# Defining preprocess hooks
Rather than placing your preprocess hooks directly in the .theme file you
can manage them in automatically discovered and lazy-loaded include files. It is
even possible to organize them in sub-folders. This feature greatly improves the
maintainability of large themes that would otherwise contain hundreds of lines
of unrelated code in your template.php file.

The include files have to follow a certain naming pattern (HOOK.preprocess.inc)
for them to be automatically discovered:

* THEMENAME_preprocess_html() = html.preprocess.inc
* THEMENAME_preprocess_page() = page.preprocess.inc
* THEMENAME_preprocess_node() = node.preprocess.inc
* THEMENAME_preprocess_comment() = comment.preprocess.inc
* THEMENAME_preprocess_region() = region.preprocess.inc

As with template files, you should replace underscores from the hook names with
hyphens:

* THEMENAME_preprocess_comment_wrapper() = comment-wrapper.preprocess.inc
* THEMENAME_preprocess_html_tag() = html-tag.preprocess.inc

Inside of each of these files you define the preprocess hook just as you would
otherwise do in your template.php file:

```
function THEMENAME_preprocess_HOOK(&$variables) {
  // Your code here.
}
```

---

_contents of the `theme/process/README.md`_

# Defining process hooks

Rather than placing your process hooks directly in the .theme file you
can manage them in automatically discovered and lazy-loaded include files. It is
even possible to organize them in sub-folders. This feature greatly improves the
maintainability of large themes that would otherwise contain hundreds of lines
of unrelated code in your template.php file.

The include files have to follow a certain naming pattern (HOOK.process.inc)
for them to be automatically discovered:

* THEMENAME_process_html() = html.process.inc
* THEMENAME_process_page() = page.process.inc
* THEMENAME_process_node() = node.process.inc
* THEMENAME_process_comment() = comment.process.inc
* THEMENAME_process_region() = region.process.inc

As with template files, you should replace underscores from the hook names with
hyphens:

* THEMENAME_process_comment_wrapper() = comment-wrapper.process.inc
* THEMENAME_process_html_tag() = html-tag.process.inc

Inside of each of these files you define the process hook just as you would
otherwise do in your template.php file:

```
function THEMENAME_process_HOOK(&$variables) {
  // Your code here.
}
```

---

## Theme directory structure

Theme directory structure when preprocess & process hooks are moved out of the .theme file into dedicated directories becomes the following:

```
|-fluffiness.breakpoints.yml
  |-fluffiness.info.yml
  |-fluffiness.libraries.yml
  |-fluffiness.theme
  |-config
  |  |-install
  |  |  |-fluffiness.settings.yml
  |  |-schema
  |  |  |-fluffiness.schema.yml
  |-css
  |  |-style.css
  |-js
  |  |-fluffiness.js
  |-images
  |  |-buttons.png
  |-logo.svg
  |-preprocess
  |  |-README.md
  |-process
  |  |-README.md
  |-screenshot.png
  |-templates
  |  |-maintenance-page.html.twig
  |  |-node.html.twig
```