You should automate repetitive tasks because today code editors already allow you to help with repetitive tasks, for example in creating the standard HTML structure, every time I have to repeat the same structure when starting a new activity, this is extremely cumbersome
It is intentional. The editor has most autocompletion disabled to force repetition. Yes, if you know what you are doing it can be cumbersome, but when you are learning, repetition is useful.
For the certificate projects, you can code them locally and then copy and paste the code into the editor. For something like the starting HTML boilerplate, you can do the same. Open an editor, use Emmet and copy it over.