Refacto palette and theme, added more colors

lua/astrobox/config.lua

@@ -0,0 +1,26 @@
+---@enum Contrast
+local CONTRASTS = {
+    soft = "soft",
+    medium = "medium",
+    hard = "hard",
+}
+
+---@class Config
+---@field contrast Contrast
+---@field float_no_borders boolean
+
+local M = {
+    ---@type Config
+    default = {
+        contrast = CONTRASTS.medium,
+        float_no_borders = true,
+    },
+}
+
+---@param user_cfg Config
+---@return Config
+function M.make_config(user_cfg)
+    return user_cfg and vim.tbl_extend("force", M.default, user_cfg) or M.default
+end
+
+return M