vento block autocompletion

[zenwork]

Adding, Removing, or Changing

Adding

Type of Modification

make editing easier and faster

What are you trying to modify

Add autocompletion suggestions for vento blocks.

see: https://github.com/ventojs/vscode-vento/blob/main/snippets%2Fvento.json

Alternatives

none

[zenwork]

Autocomplete was introduced in #154 . Some improvements and refinements should be done. There are some more autocompletion in the vscode plugin that should be added.