Documentation of Algorithim behind optuna

[arpitkh101]

This PR meets requirements related to issue in #835

[hvy]

By the way, you can check the CI (circleci) results from the links as the bottom of this PR. There is one currently failing, if you could take a look.

[arpitkh101]

@hvy
Actually, earlier I didn't add that extra line which you suggested to remove but after adding I got the same error what I was getting then.
This is just beginning of my open-source contributions, that is why I am facing such issues.
I am looking towards this error problem and if possible please suggest me changes.Sorry for inconvenience caused.

[hvy]

The current format seem correct. Indeed you need an empty line but then there was this other error that it wasn't entirely empty but contained whitespaces.

[hvy]

The documentation content basically LGTM. I left some comments. It by the way seems like you've included changes from other PRs. One way to fix your PR changes would be to rebase on the latest master, i.e. first update your local copy of the master git checkout master && git fetch <name of upstream> && git merge <name of upstream>/master --ff-only and then git rebase -i master.

[codecov-io]

Codecov Report

Merging #922 into master will decrease coverage by 0.09%.
The diff coverage is 84%.

@@            Coverage Diff            @@
##           master     #922     +/-   ##
=========================================
- Coverage   90.32%   90.22%   -0.1%     
=========================================
  Files         110      112      +2     
  Lines        9087     9293    +206     
=========================================
+ Hits         8208     8385    +177     
- Misses        879      908     +29

Impacted Files	Coverage Δ
optuna/study.py	92.72% <84%> (-0.9%)	⬇️
optuna/integration/cma.py	93.95% <0%> (ø)	⬆️
optuna/_experimental.py	100% <0%> (ø)	⬆️
optuna/progress_bar.py	48.83% <0%> (ø)
optuna/storages/rdb/alembic/versions/v1.2.0.a.py	83.33% <0%> (ø)
optuna/storages/rdb/storage.py	96.87% <0%> (+0.01%)	⬆️
optuna/storages/in_memory.py	97.83% <0%> (+0.03%)	⬆️
optuna/structs.py	94.11% <0%> (+0.04%)	⬆️
optuna/samplers/tpe/sampler.py	87.83% <0%> (+0.09%)	⬆️
tests/test_trial.py	99.24% <0%> (+0.12%)	⬆️
... and 4 more

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[hvy]

I see you're having some issues with organizing the commit history. If you really can't work it out, closing this PR and creating a new one is also fine. Just so you know.

[hvy]

I believe this is the new PR that's replacing this one #940.