[README] Add quick launch tip

[EDM115]

People can set an alias to the start command and get it running easily

Example made for PowerShell :

1. Enter notepad $PROFILE
   if this prompts an error, run New-Item -Path $PROFILE -Type File -Force before
2. Add the following to the bottom of this file :

   function Invoke-ARRPC {
       Start-Job -ScriptBlock {
           Set-Location -Path "D:\EDM115\Programmes\Discord RPC\arrpc"
           node src
       } -Name "arrpc"
   }
   
   Set-Alias -Name arrpc -Value Invoke-ARRPC

   make sure to change the path to arrpc with the actual path on your computer, and do npm install on the folder if you run it for the first time
3. Save the file, exit the notepad and run . $PROFILE

How to use :

• Start : arrpc
• See the output : Receive-Job -Name "arrpc"
• Stop : Stop-Job -Name "arrpc"

How it plays :

[masiv1001]

This is being discussed in the 51st pull request. tldr: the concept revolves around incorporating arRPC as a system service on both on Linux and Windows systems.