Completion System in Emacs

After installed, every time Emacs shows a list of files, commands, etc., vertico takes over and displays a searcheable, vertical list of items. Same examples of when vertico shows up:

By default, vertico will match items that start with the chars being typed. For example, if one types M-x load-theme RET followed by the chars “light”, it will only show themes that start with “light”. To match “light” anywhere in the theme name, prepend “*” glob to the chars, so it reads like “*light”, and then vertico will show any items that have the subsring “light” in their name, so it would match theme names like “light-blue”, “tsdh-light”, “doom-gruvbox-light” or “doom-one-light”.