add clean k tags macro

removes useless k tags in karaoke lines

clean-k-tags.lua

@@ -0,0 +1,22 @@
+local tr = aegisub.gettext
+
+script_name = tr"Clean k tags"
+script_description = tr"Remove double k tags"
+script_author = "amoethyst"
+script_version = "1.0"
+
+function special_k(subs, sel)
+
+    -- if the first tag is K/kf this would break the timing for the previous timing
+    local expr = "^(.-){\\(ko?)(%d*)[^}]-}([^{]-){\\[kK][fo]?(%d*)[^}]-}( -{(\\[kK][fo]?)%d*[^}]-}.*)$"
+
+    for _, i in ipairs(sel) do
+        line = subs[i]
+        before, tag, k1, between, k2, after = line.text:match(expr)
+        line.text = before .. "{\\" .. tag .. tonumber(k1) + tonumber(k2) .. "}" .. between .. after
+        subs[i] = line
+    end
+
+end
+
+aegisub.register_macro(script_name, script_description, special_k)