Autocompletion for Helix configuration

[quomat]

It would be nice if Helix supported autocompleting config keys in its config.toml file.

vscode has this, it makes discoverability of different config options even better.

It would depend on toml LSP, so it wouldn't need to work out of the box. If LSP fails that's fine, it's not a critical feature. But I do not know how to put the configuration symbols into it.

There have been discussions about default config file - while that's a good point, I feel like people would still delete 90% of the options and leave them defaults.

How do you feel about it?

[pascalkuthe]

You would need to generate a schema for tablo. See #3901.