Offline maps

**Description**
[example](https://codesandbox.io/s/react-leaflet-offline-5wp4i?file=/src/components/Map.js)
**Acceptance Criteria**
 <Write specifically what is need for this issue to be completed>

**Dev Notes**
[for assignee]<write down your thought process when developing this issue>

**Linked issues**
 <If there are any related issues>

<Add to milestone>
