feat(picker): Add a snacks picker with jj status command

lua/jj/init.lua

@@ -1,22 +1,24 @@
 local M = {}
 local cmd = require("jj.cmd")
-
-M.picker_config = {
-	snacks = {
-		layout = "horizontal",
-	},
-}
+local picker = require("jj.picker")
 
 --- Jujutsu plugin configuration
 --- @class jj.Config
 M.config = {
 	-- Default configuration
+	--- @type jj.picker.config
+	picker = {
+		snacks = {},
+	},
 }
 
 --- Setup the plugin
 --- @param opts jj.Config: Options to configure the plugin
 function M.setup(opts)
 	M.config = vim.tbl_deep_extend("force", M.config, opts or {})
+
+	picker.setup(opts.picker)
+
 	cmd.register_command()
 end