Add scripts for integration test setup and docs generation

* Add an OpenPGP test keypair.
 * Move script parts of documentation into script, so they can be used on a fresh Ubuntu 20.04 system
   for within a github action to setup a csaf_provider and upload documents to it for an integration test.
 * Use dineshsonachalam/markdown-autodocs in github action to automatically
   insert lines from the scripts into the docs.

Co-authored-by: Bernhard Reiter <bernhard@intevation.de>

docs/scripts/TLSClientConfigsForITest.sh

@@ -0,0 +1,45 @@
+#!/usr/bin/env bash
+
+# This file is Free Software under the MIT License
+# without warranty, see README.md and LICENSES/MIT.txt for details.
+#
+# SPDX-License-Identifier: MIT
+#
+# SPDX-FileCopyrightText: 2022 German Federal Office for Information Security (BSI) <https://www.bsi.bund.de>
+# Software-Engineering: 2022 Intevation GmbH <https://intevation.de>
+
+# It sets the right nginx configurations for enabling client certificate authentication.
+# FOLDERNAME and ORGANAME variables must be set.
+# FOLDERNAME: Where to store the CAs and keys.
+# ORGANAME: The organization name used in the CA template.
+# Usage Example: env FOLDERNAME=devca1 ORGANAME="CSAF Tools Development (internal)" ./TLSClientConfigsForITest.sh
+
+set -e
+
+NGINX_CONFIG_PATH=/etc/nginx/sites-available/default
+
+cd ~/csaf_distribution/docs/scripts/
+source ./createCCForITest.sh
+
+echo '
+        ssl_client_certificate '${SSL_CLIENT_CERTIFICATE}' # e.g. ssl_client_certificate /etc/ssl/rootca-cert.pem;
+        ssl_verify_client optional;
+        ssl_verify_depth 2;
+
+        # This example allows access to all three TLP locations for all certs.
+        location ~ /.well-known/csaf/(red|green|amber)/{
+
+            autoindex on;
+
+            # in this location access is only allowed with client certs
+            if  ($ssl_client_verify != SUCCESS){
+                # we use status code 404 == "Not Found", because we do not
+                # want to reveal if this location exists or not.
+                return 404;
+            }
+       }
+'> clientCertificateConfigs.txt
+
+sed -i "/^server {/r  ${HOME}/${FOLDERNAME}/clientCertificateConfigs.txt" $NGINX_CONFIG_PATH
+
+systemctl reload nginx