docs: add manual to readme
docs: add final text viewer and file browser diagrams
docs: add block diagrams for image viewer and text viewer
docs: finish user manual documentation
docs: add readme with documentation info
docs: fix doxygen generation
feat: add run file browser make target
feat: allow horizontal scroll in initial window
feat: make copy-executable copy another needed files to mz_apo
feat: add dialog for contextmenus on folders
feat: add files contextmenu
feat: add text viewer better keyboard controls
fix: add correct error if file cannot be executed
refactor: split local file access
refactor: split imageviewer to more functions and files
refactor: split textviewer to more functions and files
refactor: minimize filebrowser main functions
fix: incorrect table item offset