links to solutions do not work

[HMEUW]

The notebook contains several links to the solutions in the bottom of each page. In the bottom section placemarkers are used like

<a name="ex3answer">Answer to Exercise 3</a>

I figured out that we should use id instead of name, which has been deprecated. New code like:

<a id="ex3answer">Answer to Exercise 3</a>

Shall I replace it in the entire repo?

[mbakker7]

If you could submit a PR with those changes that would be great. Thanks in advance!

[HMEUW]

@mbakker7 Can you give me permission to create a PR?