Incorrect table of contents links when page contains multiple headers with the same description

[nunogoncalves03]

There is an issue with the table of contents generator on the distributed transactions page. This occurs because both the main header and a section header have identical descriptions ("Transações Distribuídas"). Consequently, the generator incorrectly links the section header with the main one, omitting the -1 index in the link. That is, the link should appear as https://resumos.leic.pt/sd/transacoes-distribuidas/#transações-distribuídas-1 instead of https://resumos.leic.pt/sd/transacoes-distribuidas/#transações-distribuídas.

How is the table of contents generated? Do you believe this issue can be addressed?

[diogotcorreia]

This seems like an issue with upstream gatsby-remark-table-of-contents.

Looks like the problem is here, https://github.com/signalwerk/gatsby-remark-table-of-contents/blob/81fedb723b1fc8308498294f68cd4d2df0f1b40f/src/index.js#L56-L60, since changing the TOC to the following works:

```toc
from-heading: 1
```

Basically, the util that is generating the ToC has no idea the other header exists, so it doesn't change the link accordingly.

I'll open an issue upstream and see if it can be fixed, but the last commit is over an year old, so I'm not sure if the project is still active.