Begin rule application

The more I think about this, the more I think it's gonna be super slow and bad. There must bve a good way of doing this, but I'm not sure how...

src/apply_rule.zig

@@ -0,0 +1,11 @@
+const Scrobble = @import("types").LastFMScrobble;
+const Rules = @import("types").Rules;
+
+pub fn applyRule(scrobble: Scrobble, rules: Rules) !Scrobble {
+    var output_scrobble: Scrobble = scrobble;
+    for (rules) |rule| {
+        for (rule.conditionals) |cond| {
+            switch (cond.match_cond) {}
+        }
+    }
+}