Add Omni Network Testnet (ethereum-lists#2973)

* add omni testnet

* use https and permanent links

* add shortName and remove whiteline

* fix formatting

* indicate eip-3091 standard

_data/chains/eip155-165.json

@@ -0,0 +1,23 @@
+{
+  "name": "Omni Testnet 1",
+  "chain": "Omni",
+  "rpc": ["https://testnet-1.omni.network"],
+  "features": [{ "name": "EIP155" }],
+  "faucets": [],
+  "nativeCurrency": {
+    "name": "Omni",
+    "symbol": "OMNI",
+    "decimals": 18
+  },
+  "infoURL": "https://docs.omni.network/",
+  "shortName": "omni_testnet",
+  "chainId": 165,
+  "networkId": 165,
+  "explorers": [
+    {
+      "name": "Omni Explorer",
+      "url": "https://testnet-1.explorer.omni.network",
+      "standard": "EIP3091"
+    }
+  ]
+}