[ImgBot] Optimize images

[njzjz]

*Total -- 2,328.36kb -> 1,804.25kb (22.51%)

/doc/images/tensorboard-distribution.png -- 265.82kb -> 175.13kb (34.12%)
/doc/images/tensorboard-graph.png -- 366.55kb -> 257.79kb (29.67%)
/doc/images/l2_loss.png -- 136.16kb -> 97.31kb (28.53%)
/doc/images/tensorboard-scalar.png -- 345.15kb -> 250.00kb (27.57%)
/doc/images/l2_energy_loss.png -- 223.01kb -> 167.06kb (25.09%)
/doc/images/l2_force_loss.png -- 176.92kb -> 133.02kb (24.81%)
/doc/images/tensorboard-histograms.png -- 814.76kb -> 723.96kb (11.15%)

Signed-off-by: ImgBotApp [email protected]

[codecov-commenter]

Codecov Report

Merging #970 (8a7fe5b) into devel (ee0ed99) will decrease coverage by 11.13%.
The diff coverage is n/a.

❗ Current head 8a7fe5b differs from pull request most recent head 2a8c658. Consider uploading reports for the commit 2a8c658 to get more accurate results

@@             Coverage Diff             @@
##            devel     #970       +/-   ##
===========================================
- Coverage   75.42%   64.28%   -11.14%     
===========================================
  Files          85        5       -80     
  Lines        6730       14     -6716     
===========================================
- Hits         5076        9     -5067     
+ Misses       1654        5     -1649     

Impacted Files	Coverage Δ
deepmd/descriptor/se_t.py
deepmd/op/__init__.py
deepmd/utils/__init__.py
deepmd/utils/neighbor_stat.py
deepmd/descriptor/se_r.py
source/op/_prod_virial_se_r_grad.py
deepmd/env.py
deepmd/entrypoints/transfer.py
deepmd/__main__.py
deepmd/infer/deep_wfc.py
... and 57 more

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