Release v2.0.0-beta0

* Update anchor.md

### 一个例子 中翻译不准确的地方
锚箱标签->锚框标签               //锚框在本书中使用的更多，锚箱看起来很奇怪
地面真实边界框->真实边界框        //ground truth中的ground翻译为了地面，但是ground truth应该指的是真实框而与地面无关

* Update anchor.md

Hey @Ryan-ly , from your inspiration, i removed other `地面` occurrences. Thanks!
Co-authored-by: Ngoldmermaid <goldpiggy@berkeley.edu>

删除了多余的逗号。

Co-authored-by: NUbuntu <ubuntu@ip-172-31-12-66.us-west-2.compute.internal>

* BUG: Fix loss and metric calculation

* Sync MSELoss with MXNet L2Loss

* Sync MSELoss with MXNet L2Loss undefit-overfit

* Sync MSELoss with MXNet L2Loss softmax-regression-scratch

* Update d2l lib for train_epoch_ch3

* Use reduction=none minibatch sgd

* Update d2l lib for train_concise_ch11

* Fix loss computation in weight decay train_concise

* drop 1/2 factor attention

* add eqmse label

* drop 1/2 underfit-overfit

* drop 1/2 softmax-scratch

* drop 1/2

* drop 1/2 tf

* drop 1/2 tf minibatch sgd

* 0.17.1

* translate minibatch sgd

* translate sequence
Co-authored-by: NAston Zhang <asv325@gmail.com>

Co-authored-by: NUbuntu <ubuntu@ip-172-31-12-66.us-west-2.compute.internal>

* align exercise with the english version

* fix

Co-authored-by: NUbuntu <ubuntu@ip-172-31-12-66.us-west-2.compute.internal>

* fix typo

* fix typo 我妈 > 我们

* in-place

* in-place

[hotfix] Add d2l-zh-2.0.0.zip

Pre-release for v2.0.0-beta0

* Fix: Epoch instead of batch

* Epoch -> epoch

* index

* finetuning-bert

* sentiment

* revert sentiment rnn

* revert sentiment rnn

* sentiment-analysis-rnn

* natural-language-inference

* sentiment-analysis-rnn