It seems like you are wanting to get average vectors on a sentence level, but your example is showing a token level vector representation.
Sentence level
Averaging sentence vectors could be done in the following way:
>>> import numpy as np
>>> np.array([nlp(doc).vector for doc in documents_list]).mean(axis=0)
This would return a single averaged vector for all sentences in documents_list
Token level
You could achieve the same on a token level by doing the following:
>>> [np.array([token.vector for token in nlp(doc)]).mean(axis=0) for doc in documents_list]
This will give you a list of averaged word vectors across tokens for each sentence. Basically a list of vectors of length len(documents_list)
Side note
As a side note, averaging vectors does not really preserve semantic structure as it implicitly makes the claim that the local context is equivalent to it's broader context. Concatenating might be a better choice in a smaller windowed context.
Make sure to test the results for your domain and task, it could work well for your task depending on your assumptions.