chore: add explanation for add_form oddities

lib/ash_phoenix/form/form.ex

@@ -940,7 +940,7 @@ defmodule AshPhoenix.Form do
             end
         end
 
-      {forms, Map.delete(params, [key, to_string(key)])}
+      {forms, params}
     end)
   end
 
@@ -1707,6 +1707,14 @@ defmodule AshPhoenix.Form do
   1. A list of atoms and integers that lead to a form in the `forms` option provided. `[:posts, 0, :comments]` to add a comment to the first post.
   2. The html name of the form, e.g `form[posts][0][comments]` to mimic the above
 
+  If you pass parameters to this function, keep in mind that, unless they are string keyed in
+  the same shape they might come from your form, then the result of `params/1` will reflect that,
+  i.e `add_form(form, "foo", %{bar: 10})`, could produce params like `%{"field" => value, "foo" => [%{bar: 10}]}`"}.
+  Notice how they are not string keyed as you would expect. However, once the form is changed (in liveview) and a call
+  to `validate/2` is made with that input, then the parameters would become what you'd expect. In this way, if you are using
+  `add_form` with not string keys/values you may not be able to depend on the shape of the `params` map (which you should ideally
+  not depend on anyway).
+
   #{Ash.OptionsHelpers.docs(@add_form_opts)}
   """
   @spec add_form(t(), String.t() | list(atom | integer), Keyword.t()) :: t()
@@ -2824,7 +2832,7 @@ defmodule AshPhoenix.Form do
         )
       end
 
-    {Map.put(forms, key, form_values), Map.delete(params, [key, to_string(key)])}
+    {Map.put(forms, key, form_values), params}
   end
 
   defp handle_form_with_params_and_no_data(