eslint-config: Disable naming-convention rule for non-js and non-ts files.

[willdawsonme]

Ran into an issue when updating to the latest version of eslint-config:

Error: Error while loading rule '@typescript-eslint/naming-convention': You have used a rule which requires parserServices to be generated. You must therefore provide a value for the "parserOptions.project" property for @typescript-eslint/parser.
Occurred while linting /Users/will/code/kablamo/os/os-frontend/packages/design-system/src/docs/Cheatsheet.mdx

@nhardy found that the naming-convention rule requires type information, so this rule should only be enabled on js and ts files.

[coveralls]

coverage: 82.059%. remained the same
when pulling 709a628 on fix/eslint-config-naming-convention-move
into 376d757 on master.