website/integrations: New VCS section and GitHub integrations (#3437)

* website/docs: create VCS section

Moved gitea and gitlab to new VCS category.

* website/docs: add GitHub-related integrations

Added GitHub Organization and GitHub Enterprise Cloud integrations. GHEC contains a note on EMU users being unsupported (GitHub limitation).

* website/docs: added GitHub links to VCS

* website/docs: Fix GitHub linter problems

website/integrations/services/github-organization/index.md

@@ -0,0 +1,53 @@
+---
+title: GitHub Organization
+---
+
+<span class="badge badge--secondary">Support level: Community</span>
+
+## What is GitHub Organizations
+
+From https://docs.github.com/en/organizations/collaborating-with-groups-in-organizations/about-organizations
+
+:::note
+Organizations are shared accounts where businesses and open-source projects can collaborate across many projects at once, with sophisticated security and administrative features.
+:::
+
+## Preparation
+
+The following placeholders will be used:
+
+-   `github.com/orgs/foo` is your GitHub organization, where `foo` is the name of your org
+-   `authentik.company` is the FQDN of the authentik Install
+
+Create an application in authentik and note the slug, as this will be used later. Create a SAML provider with the following parameters:
+
+-   ACS URL: `https://github.com/orgs/foo/saml/consume`
+-   Audience: `https://github.com/orgs/foo`
+-   Issuer: `https://github.com/orgs/foo`
+-   Binding: `Post`
+
+Under _Advanced protocol settings_, set a certificate for _Signing Certificate_.
+
+Once the provider is created, it is advised to download the signing certificate as you will need it later.
+
+## GitHub Configuration
+
+Navigate to your organization settings by going to your organization page at https://github.com/foo, then click Settings.
+
+In the left-hand navigation, scroll down to the Security section and click `Authentication security`
+
+On this page:
+
+-   Select the `Enable SAML authentication` checkbox.
+-   In `sign-on URL`, type `https://authentik.company/application/saml/<authentik application slug>/sso/binding/redirect/`
+-   For `Issuer`, type `https://github.com/orgs/foo` or the `Audience` you set in authentik
+-   For `Public certificate`, paste the _full_ signing certificate into this field.
+-   Verify that the `Signature method` and `Digest method` match your SAML provider settings in authentik.
+
+Once these fields are populated, you can use the `Test SAML configuation` button to test the authentication flow. If the flow completes successfully, you will see a green tick next to the Test button.
+
+Scroll down to hit the `Save` button below.
+
+![Screenshot showing populated GitHub organization SAML settings](ghorg_saml_settings.png)
+
+This enables SAML as an authentication _option_. If you want to _require_ SAML for your organization, visit your SSO url at `https://github.com/orgs/foo/sso` and sign in. Once signed in, you can navigate back to the `Authentication security` page and check `Require SAML SSO authentication for all members of the foo organization.`