How to write inside of a box buffer copied to a terminal buffer
Is there a way to make .write overwrite text? 

```nim
import illwill
import terminal
import math
import std/httpclient
import strutils
let SERV=(((terminalWidth()-1) / 10) * 1).floor().int
let CHAN=(((terminalWidth()-1) / 10) * 2).floor().int
let MSG= (((terminalWidth()-1) / 10) * 7).floor().int
echo SERV+CHAN+MSG,terminalWidth()

illwillInit()
var tb= newTerminalBuffer(terminalWidth(),terminalHeight())
var MenuBuff= newBoxBuffer(terminalWidth(),terminalHeight())
MenuBuff.drawRect(0,0,SERV,terminalHeight()-1,true,true)
MenuBuff.drawRect(SERV,0,SERV+CHAN,terminalHeight()-1,true,true)
MenuBuff.drawRect(SERV+CHAN,0,SERV+CHAN+MSG,terminalHeight()-1,true,true)



tb.write(1,0,"SERVERS")
tb.write(SERV+1,0,"CHANNELS")
tb.write(CHAN+SERV+1,0,"MESSAGE CONTENT")

var client = newHttpClient()
let baretext=client.getContent("https://rentry.org/DISCORDTUITEST/raw").split('\n')
for i in 0..len(baretext)-1:
  tb.write(CHAN+SERV+1,1+i,baretext[i])

illwill.write(tb,MenuBuff)

tb.display()
while getKey()!=Key.Q:discard
illwillDeinit()
```

This outputs a weird display where all the edges are wonky.