Fix toc render bug, miss closing tags, fix #73

[pietroppeter]

fix #73

• added a nice test that replicates the bug (I like how I am counting opening and closing tags)
• fix is to make sure than when next entry is at a lower level we close the appropriate number of times (a new entry might only be a single level above, but when going down the gap could be bigger than 1)
• refactored name of modules: tocs.nim -> toc_dsl.nim and renders.nim -> toc_render.nim
• unrelated: fixed gitignore to improve all executables and better ignore of docs stuff (note that putting .exe in first line would NOT work)

[pietroppeter]

should be all good, not sure if you want to give a look @HugoGranstrom. I would say we can merge this (and later also #71, I have to recall if there is something else I wanted to do there or not) and then we can tag a new release. What do you think?

well, just one very minor things I have noticed looking at PR preview: in last chapter there is a next arrow pointing to start of book (it does not seem to replicate in current scinim, I guess it might be linked to the existence of a draft chapter as last element?), see https://ed49d7c2b58457b5394a--nimibook.netlify.app/tocexample/back_to_parent.html

[HugoGranstrom]

Looks good to me 👍

well, just one very minor things I have noticed looking at PR preview: in last chapter there is a next arrow pointing to start of book (it does not seem to replicate in current scinim, I guess it might be linked to the existence of a draft chapter as last element?)

Hehe, I've noticed it as well. I consider it an easter egg 🤣 But I agree that it has something to do with a draft as the last chapter.

[pietroppeter]

well, now that it is deployed it gives an error page: https://pietroppeter.github.io/nimibook/tocexample/back_to_parent.html -> https://pietroppeter.github.io/nimibook/.html

[pietroppeter]

(opened an issue but it will wait for next release: #76 )