Provide API to provide vale configuration file by another VS Code extension

[apupier]

it would be nice to have an API to provide the vale configuration file. It will allow to provide a VS Code extension providing the Vale configuration. The benefits are:

• end-users have updated vale configuration in their environment automatically without updating the file locally (and checking if there is a new version available)
• no need to configure the vale.valeCLI.config settings

Some things to think about:

• what happens if several extension are providing an extension?
• What happens if vale.valeCLI.config is specified?

[apupier]

this one would be less important if we have #73 and/or #76