[EN] Update documentation on how to manage templates

[aphilop]

The UI of the Settings > Metadata > Templates page will be implemented to follow the new design with the issues https://github.com/huridocs/uwazi/issues/6771 and https://github.com/huridocs/uwazi/issues/6740. The documentation needs to be updated to reflect the new changes.

Affected pages in English documentation to update:

• [ ] Administrator’s guide > BUILDING YOUR INFORMATION ARCHITECTURE
• [ ] CREATING ENTITY PAGES
• [ ] Administrator’s guide > CUSTOMISING YOUR COLLECTION’S DESIGN
• [ ] Administrator’s guide > VISUALISING & ANALYSING YOUR COLLECTION’S DATA