Generate sample pipelinerun even if it exist in the project

[savitaashture]

Discussion: https://docs.google.com/document/d/1uZAC5GAGOd9-fu3S_EWadrlFYs8oxxqAk5D5mpx7gY0/edit?disco=AAAAhSNojQo

$ tkn-pac create repo

? Enter the Git repository url containing the pipelines (default: https://github.com/tektoncd/triggers):  
? Please enter the namespace where the pipeline should run (default: triggers-pipelines): 
! Namespace triggers-pipelines is not found
? Would you like me to create the namespace triggers-pipelines? Yes
✓ Repository tektoncd-triggers has been created in triggers-pipelines namespace
? There is already a file named: .tekton/pipelinerun.yaml would you like me to override it? No
! Not overwriting file, exiting...
ℹ Feel free to use the -f flag if you want to target another file name
...🚀 You can use the command "tkn pac setup" to setup a repository with webhook

Instead of asking

? There is already a file named: .tekton/pipelinerun.yaml would you like me to override it? No
! Not overwriting file, exiting...
ℹ Feel free to use the -f flag if you want to target another file name
...

its better to generate another pipelinerun something like pipelinerun-1.yaml because user has to rerun the whole command from beginning