feat: add Vim-style word search

src/main.rs

@@ -28,7 +28,7 @@ Normal: i/a insert, I/A insert at first nonblank/end, o/O new line
         _ splits above/below, | left/right; Option/Alt+h/j/k/l focuses neighboring panes
         Ctrl+Option/Alt+h/l previous/next tab; :tab.new opens current buffer in another tab
         Normal/Visual: prefix motions with counts (5j, 2w, 3n); Esc cancels count
-        u undo, U redo, : command, / search, n/N next/previous match
+        u undo, U redo, : command, / search, * search word, n/N next/previous match
         yy copies whole lines; dd deletes them; cc changes them and enters Insert; counts: 3yy, 2dd, 2cc
         dw/db cut forward/backward words on the current line; cw/cb cut the same spans and enter Insert
         Word counts before/after the operator multiply: d2w, 2cw, 2c3b; newlines are preserved