data: add some examples of expression-based rules

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

data/common/allow-api-like.yaml

@@ -0,0 +1,6 @@
+- name: allow-api-routes
+  action: ALLOW
+  expression:
+    and:
+    - '!(method == "HEAD" || method == "GET")'
+    - path.startsWith("/api/")

data/common/keep-internet-working.yaml

@@ -7,4 +7,7 @@
   action: ALLOW
 - name: robots-txt
   path_regex: ^/robots.txt$
+  action: ALLOW
+- name: sitemap
+  path_regex: ^/sitemap.xml$
   action: ALLOW

data/common/rfc-violations.yaml

@@ -0,0 +1,3 @@
+- name: no-user-agent-string
+  expression: userAgent == ""
+  action: DENY