Add IIA and value optimization related documentation

[t-tte]

Proposed changes

• Add IIA related documentation
• Add value optimization related documentation
• Add refs
• Closes IIA Integration: Documentation #192

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• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
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• Lint and unit tests pass locally with my changes
• I have added tests that prove my fix is effective or that my feature works
• I have added necessary documentation (if appropriate)
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[t-tte]

For some reason, I was not able to add @yungmsh or @zhenyuz0500 as reviewers.

[t-tte]

Thank you for your submission! We really appreciate it. Like many open source projects, we ask that you sign our Contributor License Agreement before we can accept your contribution.

t-tte seems not to be a GitHub user. You need a GitHub account to be able to sign the CLA. If you have already a GitHub account, please add the email address used for this commit to your account.
You have signed the CLA already but the status is still pending? Let us recheck it.

It seems like I got this because the email associated with the commit was incorrect (fixed now). I've of course signed the CLA in the past.

[jeongyoonlee]

Thanks @t-tte! Could you add a brief intro about value optimization methods to README.md as well? Otherwise, LGTM!

[jeongyoonlee]

Let's merge this one, and open a new one for README.md later. Thanks!