feat: scroll viewport independently of the cursor

docs/configuration.md

@@ -208,6 +208,8 @@ Normal `C` / `D` / `Y` change/delete/copy the cursor-to-line-end suffix through
 
 `f<char>` / `F<char>` seeks forward/backward on the current line in Normal and Visual, with counts such as `2fx`. Rebind `config.core.seek_forward` / `config.core.seek_backward` to a single key or leader sequence; the action then waits for a literal target character. For example, `config.bind "s", config.core.seek_forward` makes `2sx` seek the second following `x`. Pass `mode: config.modes.visual` to install a Visual route. These native-only actions do not have Ex commands.
 
+Normal and Visual Ctrl+u/Ctrl+d invoke `config.core.scroll_half_up` / `config.core.scroll_half_down` without moving carets or selection endpoints. Counts multiply the half-viewport distance. Bind `config.core.scroll_up` / `config.core.scroll_down` for one screen row per count, for example `config.bind "ctrl+e", config.core.scroll_down` to replace clone-below in Normal. Pass `mode: config.modes.visual` to rebind Visual too. These actions work in ordinary and diff text panes, use wrapped screen rows, and have no Ex commands. Cursor navigation or editing resumes caret following.
+
 ## Action reference
 
 | Available modes | Methods on `config.core` |
@@ -238,6 +240,7 @@ Normal `C` / `D` / `Y` change/delete/copy the cursor-to-line-end suffix through
 | Normal, Visual | `file_picker`, `file_explorer` |
 | Normal, Visual | `document_start`, `document_end`, `go_to_line` |
 | Normal, Visual | `seek_forward`, `seek_backward` |
+| Normal, Visual | `scroll_up`, `scroll_down`, `scroll_half_up`, `scroll_half_down` |
 | Normal, Insert, Visual | `line_start`, `line_end` |
 | Normal, Insert, Visual, Tree | `left`, `right` |
 | Normal, Insert, Visual, Selection, Tree | `down`, `up` |