fix allcontributors badge

Author: oliviasculley

README.md

@@ -1,6 +1,8 @@
 # Open Data Upstate / Greenville SC Map Layers Demo
 
+<!-- ALL-CONTRIBUTORS-BADGE:START - Do not remove or modify this section -->
 [![All Contributors](https://img.shields.io/github/all-contributors/hackgvl/open-map-data-multi-layers-demo?color=ee8449&style=flat-square)](#contributors-)
+<!-- ALL-CONTRIBUTORS-BADGE:END -->
 [![Continuous Integration](https://github.com/hackgvl/open-map-data-multi-layers-demo/actions/workflows/ci.yml/badge.svg)](https://github.com/hackgvl/open-map-data-multi-layers-demo/actions/workflows/ci.yml)
 
 This is a Vue project which allows all you to dynamically toggle on/off any of