If you are employable, a boss could reasonably hire you: you have the skills, habits, or papers that jobs ask for. It does not mean you already have a job. A student can be highly employable and still be looking. Schools and news use it when they talk about training, internships, and languages. Though actually, people stretch it. Someone may call you employable just because you interview well, or speak English, which is only part of what a workplace needs. The word is at home on CVs, courses, and government talk; it is a bit stiff for chatting about a part-time café job, where “they would hire you” is enough.