For WebSlit - '--follow' fails with panic

[koreno]

Something about the view buffer in WebSlit doesn't play well with the --follow flag:

    panic: runtime error: slice bounds out of range [3:0]
    
    goroutine 1 [running]:
    github.com/tigrawap/slit.(*viewBuffer).fill(0xc0000de148, 0x0, 0x0)
            /slit/viewbuffer.go:72 +0x53d
    github.com/tigrawap/slit.(*viewBuffer).shift(0xc0000de148, 0x1)
            /slit/viewbuffer.go:153 +0xff
    github.com/tigrawap/slit.(*viewer).navigate(0xc0000de000, 0x1)
            /slit/term.go:265 +0x47
    github.com/tigrawap/slit.(*viewer).navigateEnd(0xc0000de000)
            /slit/term.go:275 +0x75
    github.com/tigrawap/slit.(*viewer).termGui(0xc0000de000)
            /slit/term.go:465 +0x95f
    github.com/tigrawap/slit.(*Slit).Display(0xc0000b23c0)
            /slit/slit.go:109 +0x12c
    main.main()
            /slit/cmd/slit/main.go:96 +0x5ed