Problem: the old URL specifications.freedesktop.org/trash-spec/1.0/ is
dead and redirects or 404s.
Solution: update to the current URL trash/1.0/ in docs, source, and
the generation script.
Cherry-picked from: stevearc/oil.nvim#722
* wip: skeleton code for trash adapter
* refactor: split trash implementation for mac and linux
* fix: ensure we create the .Trash/$uid dir
* feat: code complete linux trash implementation
* doc: write up trash features
* feat: code complete mac trash implementation
* cleanup: remove previous, terrible, undocumented trash feature
* fix: always disabled trash
* feat: show original path of trashed files
* doc: add a note about calling actions directly
* fix: bugs in trash implementation
* fix: schedule_wrap in mac trash
* doc: fix typo and line wrapping
* fix: parsing of arguments to :Oil command
* doc: small documentation tweaks
* doc: fix awkward wording in the toggle_trash action
* fix: warning on Windows when delete_to_trash = true
* feat: :Oil --trash can open specific trash directories
* fix: show all trash files in device root
* fix: trash mtime should be sortable
* fix: shorten_path handles optional trailing slash
* refactor: overhaul the UI
* fix: keep trash original path vtext from stacking
* refactor: replace disable_changes with an error filter
* fix: shorten path names in home directory relative to root
* doc: small README format changes
* cleanup: remove unnecessary preserve_undo logic
* test: add a functional test for the freedesktop trash adapter
* test: more functional tests for trash
* fix: schedule a callback to avoid main loop error
* refactor: clean up mutator logic
* doc: some comments and type annotations
