maxi74u

fix T5 broken link in chapter 1.5

1

fixes broken link, solves issue: #918

The link to the T5 docs is broken in chapter 1.5 [How 🤗 Transformers solve tasks](https://github.com/huggingface/course/blob/main/chapters/en/chapter1/5.mdx) in the summarization section in line 134: > Encoder-decoder models like [BART](https://huggingface.co/docs/transformers/model_doc/bart) and [T5](model_doc/t5)...