Fix syntax highlight

[ryokaji]

Issue

The v1.4.4 (f4e2e63) falils syntax highlighting.
The reason is ParseResult has updated by updating the parser, so the following doesn't work anymore.

const markwhen = await parse(document.getText());
// markwhen doesn't have `timelines` property in the latest commit
markwhen.timelines.forEach((timeline: any) => {
  timeline.ranges.forEach((range: any) => {
    // ...
  }
});

How to reproduce

1. clone the repo
2. npm install && npm run build
3. launch extension via vscode

What I changed

The following have been made to allow type errors to be detected in the future if interfaces become incompatible:

• Specified that the parsing result is ParseResult
• RangeType is referred from the parser package

Result

before:

after: