Align EUI services import and code examples

[markov00]

So I've seen a difference between the EUI consuming docs and the code examples rendered in the EUI style guide.

The consuming reports that you can import services (and in the near feature experimental components like XYChart #975) using the following

import { keyCodes } from '@elastic/eui/lib/services';

but on the style guide code we are rendering imports as the following

import { keyCodes } from '@elastic/eui/services';

The regex also doesn't check for subfolders of services like the one used for tables rendering code in the style guide like

import { formatDate } from '../../../../../src/services/format';

[markov00]

Ok aligned as @elastic/eui/lib/ after 7d31e89