URL redirect list

[gsmachado]

Sometimes we change how neow3j docs pages are structured and then it breaks a bunch of URLs that were spread in the past.

Let's say, that, for example, we tweet about the Smart Contract testing and spread the following link:
https://neow3j.io/#/neo-n3/smart_contract_development/testing

But, in some months we change how the page is structured and we rename smart_contract_development to smart_contract_dev. Then the link above will be broken and will not lead to the correct page.

We would need to have a list of paths (i.e., /neo-n3-testing, etc) that we could change to pages. This would give us a lot of flexibility and less maintenance cost.