Re-arrange pages to avoid having folders/drop down when only a single page is available

Create the "for developers" category.

docs/.pages

@@ -6,3 +6,4 @@ nav:
  - mobile
  - advanced
  - training
+ - for_developers

docs/advanced/.pages

-nav:
-- web-pages
-- restore_from_trash
-- privacy_considerations
-- api_access
-- migration_from_dfs
-- corner_cases

docs/advanced/privacy_considerations/index.md → docs/advanced/privacy_considerations.md

+---
+title: Privacy considerations
+---
+
 # Privacy considerations when managing confidential data in CERNBox
 
 CERNBox is [suitable for storing personal data](https://cern.service-now.com/service-portal?id=kb_article&n=KB0003808), including sensitive personal data. CERNBox data and backups are always stored on the CERN premises.

docs/advanced/api_access/index.md → docs/for_developers/api_access.md

 # API access to data in CERNBox
 
 !!! Warning
-    This access method is reserved to developers and integrators, who need to interact with CERNBox and/or the underlying EOS storage from another service. End users should use the available regular [access methods](../../desktop/other-access-methods/desktop-mobile-access.md).
+    This access method is reserved to developers and integrators, who need to interact with CERNBox and/or the underlying EOS storage from another service. End users should use the available regular [access methods](../desktop/other-access-methods/desktop-mobile-access.md).
 
 If you are a developer and your workflow requires programmatic access to CERNBox and/or EOS, you can follow these guidelines to automate specific actions.
 
@@ -19,7 +19,7 @@ If you have created a public link on a folder with _edit_ or _uploader_ rights,
 
 `curl -T <some-file> -X PUT https://cernbox.cern.ch/remote.php/dav/public-files/<public-link-hash>/<target-filename>`
 
-Note that for _uploader_ links, the target file gets an extra hash appended to the name, to prevent collisions as the user does not have rights to list or overwrite existing content (see also [sharing](../../web/sharing/public-share.md)).
+Note that for _uploader_ links, the target file gets an extra hash appended to the name, to prevent collisions as the user does not have rights to list or overwrite existing content (see also [sharing](../web/sharing/public-share.md)).
 
 
 ## Protected shares