Move documentation translations from kovri-site

Created by: anonimal

@rehrar @serhack @erciccione @Vanchesss @Josexv1 @cryptochangements34 @jonathancross @Dridou @AMIller @alvinjoelsantos @kenshi84 @fluffypony

Merge branch 'kovri-site' into i18n

This is not an ideal solution but, because of the amount of work done on translating documentation on the kovri website (and not here, in the appropriate kovri-docs repo), a merge of the remote repo (unrelated histories) is needed as the quickest, most painless solution to grabbing all needed commits without cherry-picking.

Since the majority of content on kovri-site is documentation and translation work, and since both these repo's histories are short and repositories small, the merge is mostly effortless and will only require a small amount of post-cleanup (removing website material).

Resolves https://github.com/monero-project/kovri-site/issues/6.

Note: @jonathancross @Josexv1 @rehrar @alvinjoelsantos @erciccione: the English kovri-site documentation was not moved/taken from kovri-site because 1. kovri-site's documentation is very out of date compared to kovri-docs and 2. for me to rebase your work onto kovri-docs English documentation would require me to not retain your commit history and instead reference the work via the git-log (perhaps noting a "cherry-pick"). We have at least two options: I rebase your work onto the existing commits (I don't want to do that) or you provide new commits on those files of the changes you made in the previous English files (this only a handful of lines). Please advise.