Fix the broken format of links and references

[p16i]

Summary

It seems docstring in couples of files in keras/layers containing broken markdown hyperlinks. Please see the figure below for examples.

Related Issues

PR Overview

• This PR requires new unit tests [y/n] (make sure tests are included)
• This PR requires to update the documentation [y/n] (make sure the docs are up-to-date)
• This PR is backwards compatible [y/n]
• This PR changes the current API [y/n] (all API changes need to be approved by fchollet)

[gabrieldemarmiesse]

Thank you for the PR! It seems we were careless in merging https://github.com/keras-team/keras/pull/11160/files without looking at the generated documentation. If you have the time and it's not asking too much, could you also fix the other formatting mistakes from this #11160 ?