GitHub app example refers to token vending action that is archived

The machine-learning-apps/actions-app-token GitHub action repo noted in the README has been archived as of Dec 2022, which also uses set-output, due for deprecation in four months:

github-action/README.md

Lines 112 to 117 in 0a8bd9a

    
           - name: Get token 
        
             id: get_token 
        
             uses: machine-learning-apps/actions-app-token@master 
        
             with: 
        
               APP_PEM: ${{ secrets.APP_PEM }} 
        
               APP_ID: ${{ secrets.APP_ID }}

The README should reference a token vending GitHub Action that is maintained.

	- name: Get token
	id: get_token
	uses: machine-learning-apps/actions-app-token@master
	with:
	APP_PEM: ${{ secrets.APP_PEM }}
	APP_ID: ${{ secrets.APP_ID }}