Merge fork for measurements tool

[maks7d]

Hi, your library is providing very nice features. That's really cool !

I need a measurement tool on the graph and I have found a fork of your project which implements this tool by using a simple additional folder. I am very interested for this tool in your repo, the merge doesn't seem to heavy.
If you could merge this fork into your repo, it would be a great new feature in your project.

Here is the link to the fork : https://github.com/80sVectorz/lightweight-charts-python.
Looking forward to your thoughts,
Maxime.

[EsIstJosh]

Done.

Note:
This tool seems to be poorly implemented and unnecessary,
Future releases will likely add an option to other drawings to display the measurements if available, making this obsolete.