Add support for various JsDiff text comparison methods

[circAssimilate]

This PR is heavily inspired by #31, but differs slightly in it's approach. This is required functionality if we're going to be able to use react-diff-viewer in our product. Today, the default text diff comparison looks like this:

But it would be more desirable for the implementer to be able to specify which JsDiff method is used, creating a more desirable diff in cases like this:

Because the proposed jsDiffCompareMethod prop has a default value of diffChars, this would be a backwards compatible and a non-breaking change. disableWordDiff would still exist as a different prop and we'd simply return early if an unrecognized method name was passed.

In summary, this PR will:

• Update the example app with the text diff method options
• Add readme documentation
• Add tests for the new functionality

Some other improvements worth considering in this or subsequent PRs:

• Allowing for options documented in https://github.com/kpdecker/jsdiff/tree/v4.0.1#api

Run this locally:
(NOTE: this node version works for me but someone should probably add .nvmrc with ideal node version)

# pull this branch / PR
nvm install 12.13.0
nvm use 12.13.0
yarn
yarn build:watch 

# In separate shell
nvm use 12.13.0
yarn start:examples

Totally open to feedback and very interested in helping push this over the line!

[praneshr]

Hi @circAssimilate, thanks for this. This is really useful. I'll take a look at this over the weekend. Thanks again.

[praneshr]

LGTM. Can you check the PR comments and fix them. I'm planning to include this change in the upcoming v3.0

[circAssimilate]

Thanks for the review, @praneshr. I'll aim to get to this today!

[circAssimilate]

@praneshr, all ready for another review when you get the chance. 🎩👌

[circAssimilate]

@praneshr, out of curiosity, do you have a rough timeline of when the 3.0.0 release will happen? We're doing some internal planning and I was hoping to communicate some expected timelines.

[praneshr]

@circAssimilate I'm so sorry for the delay. v3.0 will be out by Dec 8th. I'll merge your PR with my changes. Till then, you can use the forked module.

[circAssimilate]

Sounds good, thank you!

[praneshr]

@circAssimilate Thanks for the contribution. Merging this to master. It will be released with v3

[circAssimilate]

Thank you for the support and review, @praneshr!