feat: add PawSQL docs examples and image CI

examples/Barkfile

@@ -0,0 +1,18 @@
+pawsql {
+    listen :5432
+
+    tls {
+        cert /etc/pawsql/tls/fullchain.pem
+        key /etc/pawsql/tls/privkey.pem
+    }
+
+    database bark_bistro {
+        hostname bistro.pawsql.test
+        upstream bark-bistro:5432
+    }
+
+    database wagging_tail {
+        hostname tail.pawsql.test
+        upstream wagging-tail:5432
+    }
+}