add keyword descriptions to meta schemas

[mabagoury]

The $id description is only added for now to see if updating the node module would make things work correctly.

[jdesrosiers]

I'm a little wary of the maintenance requirements of some of the more elaborate descriptions. Let's keep it to relatively simple descriptions. We can include a link to learnjsonschema.com (which I noticed is where you're getting your descriptions anyway) for more information.

[jdesrosiers]

Please rebase

[mabagoury]

This is still a work in progress. We have a bug rendering the markdown in Neovim. A \ at the end of the line is rendered as is instead of being interpreted as a hard line break.

[DarhkVoyd]

@jdesrosiers We have made the required changes to the description to keep them relatively simpler and easier to maintain.

[jdesrosiers]

Looks good other than some linting errors. After you fix the linting errors, please rebase and squash your commits. Then it'll be ready to merge.