refactor: 将默认路径从/rc更改为/leonos

统一修改代码中的默认路径，从/rc变更为/leonos，以反映系统名称变更

data/computercraft/lua/rom/programs/shell.lua

@@ -74,7 +74,7 @@ for k, v in pairs(aliases) do
   shell.setAlias(k, v)
 end
 
-local completions = "/rc/completions"
+local completions = "/leonos/completions"
 for _, prog in ipairs(fs.list(completions)) do
   dofile(fs.combine(completions, prog))
 end