Fix all docs type class and data types links

[raulraja]

All type classes and data type in the documentation site should follow the same path as the package they declared in terms of permalinks in the docs.
For example:

arrow.core.Option -> docs/arrow/core/option

All permalinks need to be modified and if possible preserve existing redirects.
This is necessary because we plan on using reflection and other introspection techniques to have some parts of the docs autogenerated at build time. Links for a given data type or type class need to be predictable so the generator can assume those paths to be there.

[Tylos]

I have been reviewing the issue and wanted to ask a coupe of questions to make sure I got everything right:

• I understand all the type classes and data classes are listed in those documentation directories. Did I missed anything?
• In each file I should modify the permalink variable in Jekyll Front Matter header so it matches the class package
• For redirects, I have checked that github pages already supports a plugin we could use. External references to documentation should keep working. Should I also update the existing relative urls or references in the project to the new permalink or rely on the redirection?

[JorgeCastilloPrz]

• Not all of them have docs yet, I think. Still this is more about updating the current route the ones available have so we can support access through some reflection techniques based on the same url pattern.
• The second one is true. Not sure if you also need to modify some links to those in the side menu. @raulraja?
• I'm not sure what you mean by redirects?

[raulraja]

By redirects I mean that we may loose traffic and position reworking the links so it'd be nice if the existing ones would redirect to the new links based on the package.seems like @Tylos has a plan for this though.

[Tylos]

Currently working on a forked version of arrow

You can access the documentation using the new url docs/arrow/core/option

Whereas docs/datatypes/option redirects to the aforementioned link

There are some issues I will keep investigating. When the user clicks on the lateral menu for sections which perform a redirect, the menu state is lost

[calvellido]

@Tylos regarding the menu state, that behaviour you are seeing is because it is set at runtime by comparing through JS the current URL with the one considered for the menu entry, which is set through Liquid for each entry in the sidebar:

arrow/modules/docs/arrow-docs/docs/js/functions.js

Line 88 in 86dd8cc

if ($this.attr('href') === current){

arrow/modules/docs/arrow-docs/docs/_data/menu.yml

Line 54 in 86dd8cc

url: /docs/datatypes/option/

arrow/modules/docs/arrow-docs/docs/_includes/_sidebar-wrapper.html

Line 16 in 86dd8cc

<a href="{% if item.url %}{{item.url}}{% else %}#{% endif %}">

Changing the URL in the menu entry might suffice, but I guess that if the URLs could be changing depending on the source code organization, this has to be considered and updated when that happens.

[pakoito]

Uh, it'd be great if the menu scrolled to the open position afterwards. It's something that's bugging me for a while :)

[Tylos]

@calvellido changing the URLs in menu.yml gets it back to work again as you said!

Do you think I should swap other internal usages of old link to the new one?