[Docs update] Documentation on Project-Service Management Guide drifted

[cannibal-kush]

https://github.com/microsoft/bedrock-cli/blob/master/guides/project-service-management-guide.md

In the following line:
bedrock project create-variable-group $VARIABLE_GROUP_NAME -r $ACR_NAME -u $SP_APP_ID -t $SP_TENANT -p $SP_PASS

The variable group will always be created on bedrock's configured Project inside Azure DevOps, which may not be the correct repository for the specific project. The -d flag should be added with instruction to user to correctly specify that value.

In the following line:
bedrock project install-lifecycle-pipeline --org-name $ORG_NAME --devops-project $DEVOPS_PROJECT --repo-url $SERVICE_REPO_URL --repo-name $SERVICE_NAME

--repo-name has been removed from this command, reference to it should be removed here.