website/docs: prepare 2023.3 release notes (#4889)

* website/docs: prepare 2023.3 release notes

Signed-off-by: Jens Langhammer <jens@goauthentik.io>

* Apply suggestions from code review

Co-authored-by: Tana M Berry <tanamarieberry@yahoo.com>
Signed-off-by: Jens L. <jens@beryju.org>

* add better docs for custom css

Signed-off-by: Jens Langhammer <jens@goauthentik.io>

---------

Signed-off-by: Jens Langhammer <jens@goauthentik.io>
Signed-off-by: Jens L. <jens@beryju.org>
Co-authored-by: Tana M Berry <tanamarieberry@yahoo.com>

website/docs/interfaces/_global/customcss.mdx

@@ -0,0 +1,59 @@
+### Custom CSS
+
+To further modify the look of authentik, a custom CSS file can be created. Creating such a file is outside the scope of this document.
+
+import Tabs from "@theme/Tabs";
+import TabItem from "@theme/TabItem";
+
+<Tabs
+  defaultValue="docker-compose"
+  values={[
+    {label: 'docker-compose', value: 'docker-compose'},
+    {label: 'Kubernetes', value: 'kubernetes'},
+  ]}>
+  <TabItem value="docker-compose">
+Create a `docker-compose.override.yml` file and add this block to mount the custom CSS file:
+
+```yaml
+version: "3.2"
+
+services:
+    server:
+        volumes:
+            - ./my-css-file.css:/web/dist/custom.css
+```
+
+Afterwards, run the upgrade commands from the latest release notes.
+
+  </TabItem>
+  <TabItem value="kubernetes">
+Create a ConfigMap with your css file:
+
+```yaml
+apiVersion: v1
+kind: ConfigMap
+metadata:
+    name: authentik-custom-css
+    namespace: authentik
+data:
+    custom.css: |
+        ...
+```
+
+Then, in the helm chart add this to your `values.yaml` file:
+
+```yaml
+volumes:
+    - name: custom-css
+      configMap:
+          name: authentik-custom-css
+volumeMounts:
+    - name: custom-css
+      mountPath: /web/dist/custom.css
+      subPath: custom.css
+```
+
+Afterwards, run the upgrade commands from the latest release notes.
+
+  </TabItem>
+</Tabs>

website/docs/interfaces/_global/global.mdx

@@ -0,0 +1,5 @@
+## Global customization
+
+import CustomCSS from "./customcss.mdx";
+
+<CustomCSS />

website/docs/interfaces/admin/customization.mdx

@@ -7,3 +7,7 @@ How many items should be retrieved per page. Defaults to 20.
 ### `settings.theme.base`
 
 Configure the base color scheme. Defaults to `automatic`, which switches between dark and light mode based on the users' browsers' preference. Choices: `automatic`, `dark`, `light`.
+
+import Global from "../_global/global.mdx";
+
+<Global />

website/docs/interfaces/flow/customization.mdx

@@ -5,3 +5,7 @@ Since flows can be executed authenticated or unauthenticated, the default settin
 ### `settings.theme.base`
 
 Configure the base color scheme. Defaults to `automatic`, which switches between dark and light mode based on the users' browsers' preference. Choices: `automatic`, `dark`, `light`.
+
+import Global from "../_global/global.mdx";
+
+<Global />

website/docs/interfaces/user/customization.mdx

@@ -58,3 +58,7 @@ Which layout to use for the Library view. Defaults to `row`. Choices: `row`, `2-
 ### `settings.locale`
 
 The locale which can be configured in the user settings by default. This can be used to preset locales for groups of users, but still let them choose their own preferred locale
+
+import Global from "../_global/global.mdx";
+
+<Global />