Restore instructions on how to sign commits/tags (#12)

Author: alcaeus

README.md

@@ -44,9 +44,13 @@ Use this action to create signed git artifacts:
 
 - name: Create signed commit
  uses: mongodb/drivers-github-tools/git-sign@v2
+ with:
+ command: "git commit -m 'Commit' -s --gpg-sign=${{ vars.GPG_KEY_ID }}"
 
 - name: Create signed tag
  uses: mongodb/drivers-github-tools/git-sign@v2
+ with:
+ command: "git tag -m 'Tag' -s --local-user=${{ vars.GPG_KEY_ID }} <tag>"
 ```
 
 ### gpg-sign
@@ -152,4 +156,4 @@ If `dry_run` is set, nothing will be published or pushed.
  product_name: winkerberos
  token: ${{ github.token }}
  dry_run: ${{ inputs.dry_run }}
-```
+```