T58: the terminal shows a scrollbar over its history, which a user asked for in issue #2 after 0.1.5, since a program that takes the mouse takes the wheel: a thumb along the right edge, in Ely's sizes and colors, stands where the view stands, and a drag moves the view through the history; none shows without history

README.md

@@ -42,6 +42,7 @@ The app writes its log to stderr. `RUST_LOG=elyterminal=debug` writes more; `tra
 ## What it does
 
 - The terminal runs on `alacritty_terminal`: 256 colors and truecolor, bold, dim, italic, five underline styles, wide characters and combining marks. Box drawing, block elements and powerline shapes are drawn as geometry, so lines join across cells. Keys follow xterm and the kitty keyboard protocol, and on Windows win32-input-mode, as Windows Terminal sends them, so herdr's shortcuts work; input methods compose at the cursor; programs can track the mouse; pastes are bracketed when a program asks; OSC 8 and plain links open with the link press below; inside herdr, herdr opens them, web links only, whole where its pane wraps them, and with Shift the terminal opens what it sees; find searches the scrollback.
+- A scrollbar along the terminal's right edge scrolls its history, even while a program takes the wheel.
 - Shell integration for zsh, bash, fish and PowerShell: each prompt reports its folder and title, and OSC 133 marks each prompt, each command and its exit status.
 - Ely peeks over the window's top edge, or up from its bottom left when the window leaves her no room above it, and moves all the time: she breathes, sways and blinks. She follows your sessions: she hops when a program waits on you, shakes at an error, cheers a finish, reads along while a program works, and dozes when all is calm for long. Press her and she winks, waking her from a doze. Drag her along the edge to move her. Settings › Terminal › Ely turns her off.
 - Sessions: new, close and switch. A bell marks a hidden session's row and makes no sound. A row's mark shows what its programs report through OSC 7501, OSC 9;4 or herdr: waiting on you, an error, work with its progress, done or idle, else a failed last command. The mark is 3 by 3 dots: work ripples and waiting dips while they last. Hover over the mark lists each report.