add numbers and date format config options and example

[RandomFractals]

based on user feedback from Tolga: https://marketplace.visualstudio.com/items?itemName=RandomFractalsInc.vscode-data-preview&ssr=false#review-details

[RandomFractals]

see perspectivejs docs with more info on recently added custom types support:

https://perspective.finos.org/docs/md/usage.html#customizing-behavior-with-perspectiveconfigjs

and this example with worker perspective config setup for custom types and formatting to integrate this new feature in data preview webview:

https://github.com/finos/perspective/blob/master/examples/simple/superstore-themed.html

[wxqwinner]

Hi friend, do you have a more detailed explanation about the display precision configuration of floating point numbers? I tried everything but it didn't work.thanks

[RandomFractals]

@wxqwinner I have not worked on this yet, but basically data view config will have new types structure with some default for floats and dates that you will be able to change similar to this setup: https://github.com/finos/perspective/blob/master/examples/simple/superstore-themed.html#L72

[RandomFractals]

perspective lib docs are really bad on this part & config options :(

found this gem for adding readable dates on saves:

finos/perspective@389d57e

will use it as a template for the date formatting hooks, default ext. setting and config options for this update

[RandomFractals]

will add ISO date default setting and date locale config options in the next v2.x release ...