Short answer
That feature is provided by a plugin called Syntastic, itself a third-party wrapper around built-in features (:help :make
, :help quickfix
), themselves using external programs (most likely eslint
). You should must read the documentation of that plugin: :help syntastic
.
Long answer
The whole point of customization is to adjust your environment to your needs. This is done by:
- identifying your needs/problems,
- looking for solutions that don't create more needs/problems,
- putting them in practice.
By downloading someone else's config you essentially gave up before the first step. Your environment is now adjusted to someone else's needs and is full of settings and plugins you may or may not need, that may or may not suit your needs. You willingly chose to install a black box you don't understand instead of actually learning your editor and configuring your environment to suit your needs.
You wanted a quick install and you get an impenetrable mess. I'd suggest you get rid of all that crap ASAP.
Lack of curiosity will get you nowhere, especially in programming.