feat: matic mainnet and mumbai testnet (polygon) (#586)

Co-authored-by: Taylor Dawson <taylorjdawson@gmail.com>

Author: yomarion

src/utilities.ts

@@ -325,6 +325,10 @@ export function networkName(id: number): string {
       return 'kovan'
     case 100:
       return 'xdai'
+    case 137:
+      return 'matic'
+    case 80001:
+      return 'mumbai'
     case 42220:
       return 'celo'
     default:
@@ -347,6 +351,10 @@ export function networkToId(network: string): number {
       return 42
     case 'xdai':
       return 100
+    case 'matic':
+      return 137
+    case 'mumbai':
+      return 80001
     case 'celo':
       return 42220
     default: