Support more lsp features

[aszenz]

Thanks for making this and improving the lives of twig developers.

Before using the vscode plugin I used https://marketplace.visualstudio.com/items?itemName=mblode.twig-language-2.

I'm missing some feature from it though:

1. Twig snippets like these

do                {% do ... %}
extends           {% extends 'template' %}
from              {% from 'template' import 'macro' %}

2. Support formatting maybe integrate with third party plugin like prettydiff
3. Some form of go-to-definition (maybe for blocks and macros initially)

[kaermorchen]

Did you try to use the both extensions together? They shouldn't conflict.

[aszenz]

Did you try to use the both extensions together? They shouldn't conflict.

Yes i could use the snippets from the library, and use this library for syntax highlighting

[moetelo]

@aszenz

Some form of go-to definition

Implemented that here for include('template.html.twig') and other template inclusion statements/functions.
#27

Please tell me if something is missing for this feature. PR review is welcomed.