Implement location components

[sevfurneaux]

⚠️ Implementing "location" components adds a lot of complexity because of required relations between pages ⚠️

A location component depends on the page’s location. For example:

• next-page: can show the content of the next page
• previous-page: can show the content of the previous page
• pages-in-folder: can show the content of the pages in the same folder
• parent-pages: can show the content of the pages above the current folder
• subpages: can show the content of the pages below the current folder