feat(textarea): add help to textarea key bindings (#418)

Author: TravisYeah

textarea/textarea.go

@@ -63,30 +63,30 @@ type KeyMap struct {
 // DefaultKeyMap is the default set of key bindings for navigating and acting
 // upon the textarea.
 var DefaultKeyMap = KeyMap{
-	CharacterForward:        key.NewBinding(key.WithKeys("right", "ctrl+f")),
-	CharacterBackward:       key.NewBinding(key.WithKeys("left", "ctrl+b")),
-	WordForward:             key.NewBinding(key.WithKeys("alt+right", "alt+f")),
-	WordBackward:            key.NewBinding(key.WithKeys("alt+left", "alt+b")),
-	LineNext:                key.NewBinding(key.WithKeys("down", "ctrl+n")),
-	LinePrevious:            key.NewBinding(key.WithKeys("up", "ctrl+p")),
-	DeleteWordBackward:      key.NewBinding(key.WithKeys("alt+backspace", "ctrl+w")),
-	DeleteWordForward:       key.NewBinding(key.WithKeys("alt+delete", "alt+d")),
-	DeleteAfterCursor:       key.NewBinding(key.WithKeys("ctrl+k")),
-	DeleteBeforeCursor:      key.NewBinding(key.WithKeys("ctrl+u")),
-	InsertNewline:           key.NewBinding(key.WithKeys("enter", "ctrl+m")),
-	DeleteCharacterBackward: key.NewBinding(key.WithKeys("backspace", "ctrl+h")),
-	DeleteCharacterForward:  key.NewBinding(key.WithKeys("delete", "ctrl+d")),
-	LineStart:               key.NewBinding(key.WithKeys("home", "ctrl+a")),
-	LineEnd:                 key.NewBinding(key.WithKeys("end", "ctrl+e")),
-	Paste:                   key.NewBinding(key.WithKeys("ctrl+v")),
-	InputBegin:              key.NewBinding(key.WithKeys("alt+<", "ctrl+home")),
-	InputEnd:                key.NewBinding(key.WithKeys("alt+>", "ctrl+end")),
-
-	CapitalizeWordForward: key.NewBinding(key.WithKeys("alt+c")),
-	LowercaseWordForward:  key.NewBinding(key.WithKeys("alt+l")),
-	UppercaseWordForward:  key.NewBinding(key.WithKeys("alt+u")),
-
-	TransposeCharacterBackward: key.NewBinding(key.WithKeys("ctrl+t")),
+	CharacterForward:        key.NewBinding(key.WithKeys("right", "ctrl+f"), key.WithHelp("right", "character forward")),
+	CharacterBackward:       key.NewBinding(key.WithKeys("left", "ctrl+b"), key.WithHelp("left", "character backward")),
+	WordForward:             key.NewBinding(key.WithKeys("alt+right", "alt+f"), key.WithHelp("alt+right", "word forward")),
+	WordBackward:            key.NewBinding(key.WithKeys("alt+left", "alt+b"), key.WithHelp("alt+left", "word backward")),
+	LineNext:                key.NewBinding(key.WithKeys("down", "ctrl+n"), key.WithHelp("down", "next line")),
+	LinePrevious:            key.NewBinding(key.WithKeys("up", "ctrl+p"), key.WithHelp("up", "previous line")),
+	DeleteWordBackward:      key.NewBinding(key.WithKeys("alt+backspace", "ctrl+w"), key.WithHelp("alt+backspace", "delete word backward")),
+	DeleteWordForward:       key.NewBinding(key.WithKeys("alt+delete", "alt+d"), key.WithHelp("alt+delete", "delete word forward")),
+	DeleteAfterCursor:       key.NewBinding(key.WithKeys("ctrl+k"), key.WithHelp("ctrl+k", "delete after cursor")),
+	DeleteBeforeCursor:      key.NewBinding(key.WithKeys("ctrl+u"), key.WithHelp("ctrl+u", "delete before cursor")),
+	InsertNewline:           key.NewBinding(key.WithKeys("enter", "ctrl+m"), key.WithHelp("enter", "insert newline")),
+	DeleteCharacterBackward: key.NewBinding(key.WithKeys("backspace", "ctrl+h"), key.WithHelp("backspace", "delete character backward")),
+	DeleteCharacterForward:  key.NewBinding(key.WithKeys("delete", "ctrl+d"), key.WithHelp("delete", "delete character forward")),
+	LineStart:               key.NewBinding(key.WithKeys("home", "ctrl+a"), key.WithHelp("home", "line start")),
+	LineEnd:                 key.NewBinding(key.WithKeys("end", "ctrl+e"), key.WithHelp("end", "line end")),
+	Paste:                   key.NewBinding(key.WithKeys("ctrl+v"), key.WithHelp("ctrl+v", "paste")),
+	InputBegin:              key.NewBinding(key.WithKeys("alt+<", "ctrl+home"), key.WithHelp("alt+<", "input begin")),
+	InputEnd:                key.NewBinding(key.WithKeys("alt+>", "ctrl+end"), key.WithHelp("alt+>", "input end")),
+
+	CapitalizeWordForward: key.NewBinding(key.WithKeys("alt+c"), key.WithHelp("alt+c", "capitalize word forward")),
+	LowercaseWordForward:  key.NewBinding(key.WithKeys("alt+l"), key.WithHelp("alt+l", "lowercase word forward")),
+	UppercaseWordForward:  key.NewBinding(key.WithKeys("alt+u"), key.WithHelp("alt+u", "uppercase word forward")),
+
+	TransposeCharacterBackward: key.NewBinding(key.WithKeys("ctrl+t"), key.WithHelp("ctrl+t", "transpose character backward")),
 }
 
 // LineInfo is a helper for keeping track of line information regarding