feat: implement imprint/impressum support (#706)

* feat: implement imprint/impressum support

Closes #362

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore(docs/anubis): enable an imprint

Signed-off-by: Xe Iaso <me@xeiaso.net>

* chore: spelling

Signed-off-by: Xe Iaso <me@xeiaso.net>

* docs: fix the end of the sentence, comment out a default impressum

Signed-off-by: Xe Iaso <me@xeiaso.net>

* docs: link back to impressum page

Signed-off-by: Xe Iaso <me@xeiaso.net>

---------

Signed-off-by: Xe Iaso <me@xeiaso.net>

lib/policy/config/testdata/bad/impressum-no-footer.yaml

@@ -0,0 +1,11 @@
+bots:
+  - name: simple-weight-adjust
+    action: WEIGH
+    user_agent_regex: Mozilla
+    weight:
+      adjust: 5
+
+impressum:
+  page:
+    title: Test
+    body: <p>This is a test</p>

lib/policy/config/testdata/bad/impressum-no-page-contents.yaml

@@ -0,0 +1,10 @@
+bots:
+  - name: simple-weight-adjust
+    action: WEIGH
+    user_agent_regex: Mozilla
+    weight:
+      adjust: 5
+
+impressum:
+  footer: "Hi there these are WORDS on the INTERNET."
+  page: {}

lib/policy/config/testdata/good/impressum.yaml

@@ -0,0 +1,10 @@
+bots:
+  - name: simple
+    action: CHALLENGE
+    user_agent_regex: Mozilla
+
+impressum:
+  footer: "Hi these are WORDS on the INTERNET."
+  page:
+    title: Test
+    body: <p>This is a test</p>