feat: add deprecation warnings for updated options

lua/cyberdream/config.lua

@@ -106,9 +106,55 @@ local default_options = {
 ---@type Config
 M.options = {}
 
+-- TODO: Remove post v5.0.0
+local function notify_deprecation(old_option, new_option)
+    vim.defer_fn(function()
+        vim.notify(
+            string.format("The '%s' is deprecated!\n\nUse '%s' instead.", old_option, new_option),
+            3,
+            { title = "cyberdream.nvim" }
+        )
+    end, 1000)
+end
+
+-- TODO: Remove post v5.0.0
+local function handle_theme_deprecation(options)
+    if not options.theme then
+        return options
+    end
+
+    notify_deprecation("theme table", "root table")
+
+    local theme_mappings = {
+        variant = true,
+        saturation = true,
+        colors = true,
+        highlights = true,
+        overrides = true,
+    }
+
+    for key in pairs(theme_mappings) do
+        if options.theme[key] then
+            options[key] = options.theme[key]
+        end
+    end
+
+    return options
+end
+
 ---@param options Config|nil
 function M.setup(options)
-    M.options = vim.tbl_deep_extend("force", {}, default_options, options or {})
+    options = options or {}
+    ---@diagnostic disable: undefined-field
+    if options.borderless_telescope ~= nil then
+        notify_deprecation("borderless_telescope", "borderless_pickers")
+        options.borderless_pickers = options.borderless_telescope
+    end
+    ---@diagnostic enable: undefined-field
+    options = handle_theme_deprecation(options)
+
+    --- TODO: Delete everything above post v5.0.0
+    M.options = vim.tbl_deep_extend("force", {}, default_options, options)
     vim.g.cyberdream_opts = M.options
 end