Intellisense doesn't trigger for multi-line functions

Some learnings from here: https://github.com/microsoft/vscode/issues/99504, though not helpful for this plugin to get triggered only when required.

Some pointers I need to keep in mind:

VSCode autocomplete triggers plugins registered for completion with special characters like - a lot of times.
If we return an empty list: [], autocomplete will not get triggered unless autocomplete popup closes and user presses our trigger character again.
We need to backtrack characters and find out if for the current trigger we need to show completion items or not intelligently, without affecting user's usual development, and bombarding with suggestions on any random trigger character press.

I haven't tried using LSP, but with above findings, I don't think there would be any difference.

willofindie / vscode-cssvar