off topic: I've found tide-mode[0] to be pretty good to use with typescript on Emacs
As an aside, I don't recommend following the article author in disabling Eldoc integration. Enabled, that will give you types for the thing at point in the message area, which is often quite useful and especially so with unfamiliar codebases.
It’s very fast and usually brings you right to a definition — unless your method/function is called very unspecifically.
sudo apt install exuberant-ctags
ctags-exuberant --list-languages