Update docs

Re-arrange pages to avoid having folders/drop-down when only a single page is available. Create the "for developers" category and include the docs of the file picker that were being served by filepicker.cernbox.cern.ch (I removed it when updating to Alma 9 + cleaning up).

requested review from @lopresti

added 4 commits

• ffaeb2c3 - Re-arrange pages to avoid having folders/drop down when only a single page is available
• 0c81a49a - Api access: format commands
• 67fa6cca - Add file picker documentation
• cbaa3735 - Colorise code blocks

Compare with previous version

approved this merge request

merged

mentioned in commit d779f058