yaml - Including variables in jekyll from given file -

i want have variable assignments placed in single txt file or similar in jekyll, , have them included in front matter assignment. instead of this:

--- variable1: abc variable2: 123 --- 

i can have this:

--- {% include variables.txt %}   --- 

the purpose of have website editable technologically inexperienced client. want abstract out core site structure things need edited as possible - without setting cms, or moving dynamic site (so can still hosted on github pages)

you throw of variables _config.yml file , can accessed this:

{{ site.variable1 }}