Solve the problem with the original exclude file-mlfundamental part

[Lola-jo]

前期在 md2ipynb 的过程中，有一些 notebook build 不通过，所以暂时放到了 config exclude 里面

现在 md2ipynb 收尾，那么就需要把这些 notebook 的 build 不通过的问题解决

• - 'ml-fundamentals/classification/introduction-to-classification.ipynb'
• - 'ml-fundamentals/build-a-web-app-to-use-a-machine-learning-model.md'
• - 'ml-fundamentals/regression/managing-data.md'
• - 'ml-fundamentals/regression/loss-function.ipynb'