Remove README from docs

[akihironitta]

What does this PR do?

This is also a suggestion to remove readme from the docs. I believe no one really sees this ugly readme (as shown in below image) on the docs... Also, readme is not linked from anywhere on the docs, so I'm sure anyone doen't look at this readme page...
https://pytorch-lightning-bolts.readthedocs.io/en/latest/readme.html

Before submitting

• Was this discussed/approved via a Github issue? (no need for typos and docs improvements)
• Did you read the contributor guideline, Pull Request section?
• Did you make sure your PR does only one thing, instead of bundling different changes together?
• Did you make sure to update the documentation with your changes?
• Did you write any new necessary tests? [not needed for typos/docs]
• Did you verify new and existing tests pass locally with your changes?
• If you made a notable change (that affects users), did you update the CHANGELOG?

PR review

• Is this pull request ready for review? (if not, please submit in draft mode)

Anyone in the community is free to review the PR once the tests have passed.
If we didn't discuss your PR in Github issues there's a high chance it will not be merged.

Did you have fun?

Make sure you had fun coding 🙃

[codecov]

Codecov Report

Merging #503 (a42a104) into master (8a4cf8f) will decrease coverage by 0.53%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #503      +/-   ##
==========================================
- Coverage   79.58%   79.04%   -0.54%     
==========================================
  Files         102      102              
  Lines        5921     5912       -9     
==========================================
- Hits         4712     4673      -39     
- Misses       1209     1239      +30     

Flag	Coverage Δ
cpu	25.77% <ø> (+0.12%)	⬆️
pytest	25.77% <ø> (+0.12%)	⬆️
unittests	78.55% <ø> (-0.54%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
pl_bolts/datasets/cifar10_dataset.py	71.73% <0.00%> (-26.09%)	⬇️
pl_bolts/datasets/base_dataset.py	81.81% <0.00%> (-13.64%)	⬇️
pl_bolts/models/rl/dqn_model.py	78.98% <0.00%> (-1.73%)	⬇️
pl_bolts/__init__.py	100.00% <0.00%> (ø)
pl_bolts/losses/rl.py	100.00% <0.00%> (ø)
pl_bolts/utils/warnings.py	100.00% <0.00%> (ø)
pl_bolts/utils/arguments.py	96.15% <0.00%> (ø)
pl_bolts/callbacks/printing.py	71.18% <0.00%> (ø)
pl_bolts/models/vision/unet.py	98.03% <0.00%> (ø)
pl_bolts/models/mnist_module.py	100.00% <0.00%> (ø)
... and 58 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 8a4cf8f...a42a104. Read the comment docs.

[Borda]

I would keep it and just remove all badges?

[akihironitta]

@Borda As far as I confirmed, Introduction Guide already has most of the content in readme. Would you still think it's better to keep readme in the docs?

[Borda]

@akihironitta mind check failing tests?