support word based diffs

[extrawurst]

see https://github.com/mitsuhiko/similar
or dandavison/delta#317 (if it would be a library)
or Wilfred/difftastic#216 (if it would be a library)
or https://github.com/dtolnay/dissimilar (lacks proper api ATM)

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[disrupted]

this seems to be currently in progress dandavison/delta#398

[UncleInf]

Does dandavison/delta#398 make using delta (and may be side by side diffing) any closer?
On separate note maybe in the mean time we could have a "button" to call external diff?

[extrawurst]

@UncleInf that PR seems quiet outdated (conflicts) and unmaintained. I also do not see an example of how to use delta as a library in the PR changes, so it is hard to say.