migrate legacy to v3

Hi guys,

Hope you are all well !

I tried to find some documentation but could not find it. How to migrate legacy termui integration to v3...

```bash
./dashboard.go:18:15: undefined: termui.NewList
./dashboard.go:24:26: undefined: termui.NewPar
./dashboard.go:30:27: undefined: termui.NewPar
./dashboard.go:36:23: undefined: termui.NewPar
./dashboard.go:42:25: undefined: termui.NewPar
./dashboard.go:48:21: undefined: termui.NewPar
./dashboard.go:54:24: undefined: termui.NewPar
./dashboard.go:60:20: undefined: termui.NewPar
./dashboard.go:66:17: undefined: termui.NewPar
./dashboard.go:120:17: undefined: termui.Body
```

What is replacing ?
termui.NewList()
termui.NewPar()
termui.Body

here is the code:
```go
package main

import (
"fmt"
"time"

"github.com/gizak/termui/v3"
)

func dashboard(stopTheUI, stopTheCrawler chan bool) {
if err := termui.Init(); err != nil {
panic(err)
}
defer termui.Close()

var snapshots []Snapshot

logWindow := termui.NewList()
logWindow.ItemFgColor = termui.ColorYellow
logWindow.BorderLabel = "Log"
logWindow.Height = 22
logWindow.Y = 0

totalBytesDownloaded := termui.NewPar("")
totalBytesDownloaded.Height = 3
totalBytesDownloaded.TextFgColor = termui.ColorWhite
totalBytesDownloaded.BorderLabel = "Data downloaded"
totalBytesDownloaded.BorderFg = termui.ColorCyan

totalNumberOfRequests := termui.NewPar("")
totalNumberOfRequests.Height = 3
totalNumberOfRequests.TextFgColor = termui.ColorWhite
totalNumberOfRequests.BorderLabel = "URLs crawled"
totalNumberOfRequests.BorderFg = termui.ColorCyan

requestsPerSecond := termui.NewPar("")
requestsPerSecond.Height = 3
requestsPerSecond.TextFgColor = termui.ColorWhite
requestsPerSecond.BorderLabel = "URLs/second"
requestsPerSecond.BorderFg = termui.ColorCyan

averageResponseTime := termui.NewPar("")
averageResponseTime.Height = 3
averageResponseTime.TextFgColor = termui.ColorWhite
averageResponseTime.BorderLabel = "Average response time"
averageResponseTime.BorderFg = termui.ColorCyan

numberOfWorkers := termui.NewPar("")
numberOfWorkers.Height = 3
numberOfWorkers.TextFgColor = termui.ColorWhite
numberOfWorkers.BorderLabel = "Number of workers"
numberOfWorkers.BorderFg = termui.ColorCyan

averageSizeInBytes := termui.NewPar("")
averageSizeInBytes.Height = 3
averageSizeInBytes.TextFgColor = termui.ColorWhite
averageSizeInBytes.BorderLabel = "Average response size"
averageSizeInBytes.BorderFg = termui.ColorCyan

numberOfErrors := termui.NewPar("")
numberOfErrors.Height = 3
numberOfErrors.TextFgColor = termui.ColorWhite
numberOfErrors.BorderLabel = "Number of 4xx errors"
numberOfErrors.BorderFg = termui.ColorCyan

elapsedTime := termui.NewPar("")
elapsedTime.Height = 3
elapsedTime.TextFgColor = termui.ColorWhite
elapsedTime.BorderLabel = "Elapsed time"
elapsedTime.BorderFg = termui.ColorCyan

draw := func() {

snapshot := stats.LastSnapshot()

// ignore empty updates
if snapshot.Timestamp().IsZero() {
return
}

// don't update if there is no new snapshot available
if len(snapshots) > 0 {
previousSnapShot := snapshots[len(snapshots)-1]
if snapshot.Timestamp() == previousSnapShot.Timestamp() {
return
}
}

// capture the latest snapshot
snapshots = append(snapshots, snapshot)

// log messages
logWindow.Items = stats.LastLogMessages(20)

// total number of requests
totalNumberOfRequests.Text = fmt.Sprintf("%d", snapshot.TotalNumberOfRequests())

// total number of bytes downloaded
totalBytesDownloaded.Text = formatBytes(snapshot.TotalSizeInBytes())

// requests per second
requestsPerSecond.Text = fmt.Sprintf("%.1f", snapshot.RequestsPerSecond())

// average response time
averageResponseTime.Text = fmt.Sprintf("%s", snapshot.AverageResponseTime())

// number of workers
numberOfWorkers.Text = fmt.Sprintf("%d", snapshot.NumberOfWorkers())

// average request size
averageSizeInBytes.Text = formatBytes(snapshot.AverageSizeInBytes())

// number of errors
numberOfErrors.Text = fmt.Sprintf("%d", snapshot.NumberOfErrors())

// time since first snapshot
timeSinceStart := time.Now().Sub(snapshots[0].Timestamp())
elapsedTime.Text = fmt.Sprintf("%s", timeSinceStart)

termui.Render(termui.Body)
}

termui.Body.AddRows(
termui.NewRow(
termui.NewCol(12, 0, logWindow),
),
termui.NewRow(
termui.NewCol(3, 0, totalBytesDownloaded),
termui.NewCol(3, 0, totalNumberOfRequests),
termui.NewCol(3, 0, requestsPerSecond),
termui.NewCol(3, 0, averageResponseTime),
),
termui.NewRow(
termui.NewCol(3, 0, numberOfWorkers),
termui.NewCol(3, 0, numberOfErrors),
termui.NewCol(3, 0, averageSizeInBytes),
termui.NewCol(3, 0, elapsedTime),
),
)

termui.Body.Align()

termui.Render(termui.Body)

termui.Handle("/sys/wnd/resize", func(e termui.Event) {
termui.Body.Width = termui.TermWidth()
termui.Body.Align()
termui.Clear()
termui.Render(termui.Body)
})

termui.Handle("/sys/kbd/q", func(termui.Event) {
stopTheCrawler <- true

termui.StopLoop()
})

termui.Handle("/timer/1s", func(e termui.Event) {
draw()
})

// stop when the crawler is done
go func() {
select {
case <-stopTheUI:
// wait 10 seconds before closing the ui
time.Sleep(time.Second * 10)
termui.StopLoop()
}
}()

termui.Loop()
}
```

Cheers,
X

The affected entry point is dashboard.go, especially lines 18-120, and the missing symbols are termui.NewList, termui.NewPar, and termui.Body. Start by checking the v3 package API for replacements and comparing each use in the supplied example. Done means a migration note identifies the v3 equivalents and shows an updated example that builds.

Written by the indexing model from the issue text.