Migrate to Docusaurus (#329)

* docs: initial migration to docusaurus

* website: add custom font, update blurbs and icons

* website: update splash

* root: update links to docs

* flows: use .pbflow extension so docusaurus doesn't mangle the files

* e2e: workaround prospector

* Squashed commit of the following:

commit 1248585dca
Author: Jens Langhammer <jens.langhammer@beryju.org>
Date:   Sun Nov 15 20:46:53 2020 +0100

    e2e: attempt to fix prospector error again

commit 1319c480c4
Author: Jens Langhammer <jens.langhammer@beryju.org>
Date:   Sun Nov 15 20:41:35 2020 +0100

    ci: install previous python version for upgrade testing

* web: update accent colours and format

* website: format markdown files

* website: fix colours for text

* website: switch to temporary accent colour to improve readability

* flows: fix path for TestTransferDocs

* flows: fix formatting of tests

website/docs/integrations/sources/active-directory/index.md

@@ -0,0 +1,57 @@
+---
+title: Active Directory
+---
+
+## Preparation
+
+The following placeholders will be used:
+
+-   `ad.company` is the Name of the Active Directory domain.
+-   `passbook.company` is the FQDN of the passbook install.
+
+## Active Directory Setup
+
+1. Open Active Directory Users and Computers
+
+2. Create a user in Active Directory, matching your naming scheme
+
+    ![](./01_user_create.png)
+
+3. Give the User a password, generated using for example `pwgen 64 1`.
+
+4. Open the Delegation of Control Wizard by right-clicking the domain.
+
+5. Select the passbook service user you've just created.
+
+6. Ensure the "Reset user password and force password change at next logon" Option is checked.
+
+    ![](./02_delegate.png)
+
+## passbook Setup
+
+In passbook, create a new LDAP Source in Administration -> Sources.
+
+Use these settings:
+
+-   Server URI: `ldap://ad.company`
+
+    For passbook to be able to write passwords back to Active Directory, make sure to use `ldaps://`
+
+-   Bind CN: `<name of your service user>@ad.company`
+-   Bind Password: The password you've given the user above
+-   Base DN: The base DN which you want passbook to sync
+-   Property Mappings: Select all and click the right arrow
+
+The other settings might need to be adjusted based on the setup of your domain.
+
+-   Addition User/Group DN: Additional DN which is _prepended_ to your Base DN for user synchronization.
+-   Addition Group DN: Additional DN which is _prepended_ to your Base DN for group synchronization.
+-   User object filter: Which objects should be considered users.
+-   Group object filter: Which objects should be considered groups.
+-   User group membership field: Which user field saves the group membership
+-   Object uniqueness field: A user field which contains a unique Identifier
+-   Sync parent group: If enabled, all synchronized groups will be given this group as a parent.
+
+After you save the source, a synchronization will start in the background. When its done, you cen see the summary on the System Tasks page.
+
+![](./03_pb_status.png)