Be able to store IDE plugin config in the .spectral.yml

[mskonovalov]

User story.
As a developer, I can define the IDE plugins config (Spectral for VSCode and Spectral for Intellij Idea) in the .spectral.yml file, so that I can commit it into git and I don't need to configure it manually every time on every computer.

Is your feature request related to a problem?
Spectral has 2 IDE plugins (https://plugins.jetbrains.com/plugin/18520-spectral and https://github.com/stoplightio/vscode-spectral). The parameters they allow to configure are:

• path to ruleset
• glob of validated files (VSCode supports !-notation for exclusion, not sure about Intellij)
• (VsCode only) language to validate.

Describe the solution you'd like
I'd like to put those params validateFiles and validateLanguages into root .spectral.yml file and commit it into git.
Then running spectral CLI in the root folder without arguments will actually use those params.