docs: add branding reference guide (#3549)

This adds official branding in PSD/SVG/PNG format and a guide on requested usage.

Closes #3484.

docs/content/en/reference/guides/branding.md

@@ -0,0 +1,54 @@
+---
+title: "Branding"
+description: "This guide highlights information about Authelia's branding assets"
+lead: "This guide highlights information about Authelia's branding assets."
+date: 2022-05-31T11:13:56+10:00
+draft: false
+images: []
+menu:
+  reference:
+    parent: "guides"
+weight: 220
+toc: true
+---
+
+## Usage
+
+The images are currently licensed under the same [Apache 2.0](https://github.com/authelia/authelia/blob/master/LICENSE)
+as everything else in the repository. It is requested however that with all of our branding that the only modifications
+made to it are related to layout. Examples of layout changes include:
+
+- Adjusting the Spacing Around Images
+- Adjusting the Size of the Images
+
+If you have a particular adjustment you'd like to make that does not fit within these categories we kindly request that
+you discuss it with the team in advance.
+
+## Location
+
+The assets utilized for branding Authelia can be found in the below locations.
+
+### Logo
+
+The logo is just the Authelia circle logo without any text.
+
+#### Logo Files
+
+[PSD](https://www.authelia.com/images/branding/logo.psd) | [SVG](https://www.authelia.com/images/branding/logo.svg) | [PNG](https://www.authelia.com/images/branding/logo.png)
+
+#### Logo Example
+
+{{< figure src="/images/branding/logo.svg" link="/images/branding/logo.svg" target="_blank" alt="Authelia Logo" height="150" >}}
+
+### Title
+
+The title is the Authelia circle logo with the `authelia` branded text.
+
+#### Title Files
+
+[PSD](https://www.authelia.com/images/branding/title.psd) | [SVG](https://www.authelia.com/images/branding/title.svg) | [PNG](https://www.authelia.com/images/branding/title.png)
+
+#### Title Example
+
+{{< figure src="/images/branding/title.svg" link="/images/branding/title.svg" target="_blank" alt="Authelia Title" height="150" >}}
+