Note that the list of adverb classes your book gave you should not be interpreted as exhaustive. As far as the classification of adverbs is semantic, i.e. based on meaning, it is easy to find subclasses: local can be a place (dort), the target of movement (dortin) or the source of movement (dorther); temporal can be a point in time (heute), a frequency (täglich) or a duration (stundenlang); and so on.
Also note that adverbs meaning is only one dimension in which adverbs can be classified. For instance, some of them are deictic, i.e. they refer to the context of the utterance, such as hier, dorthin, jetzt. Others are conjunctive, i.e. they link clauses. This is the category jedoch belongs in.
Erstmals verwendet wurde der Begriff [Hypermedia] 1965 von Ted Nelson. Die Idee vernetzter Medien ist jedoch weitaus älter.
Conjunctive adverbs can be classified according to meaning similar to the way conjunctions are classified. In the sentence above, there is a contrast between the ages of the term hypermedia and the corresponding idea: the former is relatively young,
yet the latter is relatively old. In the usual classification of conjunctions according to meaning, this is an adversative meaning, i.e. one expressing a contrast.
So jedoch is a conjunctive adverb with adversative meaning.