Include autosquash feature in README installation section

Author: samholmes

README.md

@@ -18,16 +18,22 @@ on:
 jobs:
   rebase:
     name: Rebase
-    if: github.event.issue.pull_request != '' && contains(github.event.comment.body, '/rebase')
-    runs-on: ubuntu-latest
+    if: >-
+      github.event.issue.pull_request != '' && 
+      (
+        contains(github.event.comment.body, '/rebase') || 
+        contains(github.event.comment.body, '/autosquash')
+      )    runs-on: ubuntu-latest
     steps:
       - name: Checkout the latest code
         uses: actions/checkout@v2
         with:
           token: ${{ secrets.GITHUB_TOKEN }}
           fetch-depth: 0 # otherwise, you will fail to push refs to dest repo
       - name: Automatic Rebase
-        uses: cirrus-actions/[email protected]
+        uses: samholmes/rebase@autosquash
+        with:
+          autosquash: ${{ contains(github.event.comment.body, '/autosquash') || contains(github.event.comment.body, '/rebase-autosquash') }}
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
 ```