feat(indent): Implement basic indent for gdscript.

Indent is not handled correctly when adding new lines.
It seems that functions/loops/etc. are not recognized until they have at
least one indented block.

For example, if you enter a newline after `func foo():`, the cursor will
not be indented. If you manually indent and add a line like `pass`,
e.g.:

```
func foo():
    pass
```

now any insertions above or below `pass` will be indented correctly.
This might be an issue with the grammar, as it seems to apply to highlights
as well.

The following will not be highligted

```
func foo():
```

However, the following will be:

```
func foo():
    pass
```

0 files changed, 0 insertions, 0 deletions