TypeScript: no type for defaultFlamegraphTooltip

[nickgirardo]

Describe the bug
The function defaultFlamegraphTooltip is exported from your distribution index, however no type is present in your index.d.ts.

Without a type exported, a Typescript compiler does not think the function exists and will refuse to compile.

To Reproduce
Steps to reproduce the behavior:

1. Create a new typescript file
2. Import defaultFlamegraphTooltip from your library (import { defaultFlamegraphTooltip } from 'd3-flame-graph';)
3. See error TS2305: Module '"d3-flame-graph"' has no exported member 'defaultFlamegraphTooltip'.

Expected behavior
If types were set this would compile with no issue. The function is correctly exported, so if I prepend the line above with //@ts-ignore I can continue without issue. This is, however, obviously not ideal.

Desktop (please complete the following information):

• OS: Linux
• Browser: Firefox
• Version: 90.0

Additional context
For this issue my desktop information might not be too relevant. My Typescript version is "4.4.2"