add eCash info and logo (#17467)

blockchains/ecash/info/info.json

@@ -0,0 +1,29 @@
+{
+    "name": "eCash",
+    "website": "https://e.cash/",
+    "description": "eCash is an electronic cash platform that allows peer-to-peer online cash payments.",
+    "explorer": "https://explorer.bitcoinabc.org",
+    "research": "https://research.binance.com/en/projects/ecash",
+    "symbol": "XEC",
+    "type": "coin",
+    "decimals": 2,
+    "status": "active",
+    "links": [
+        {
+            "name": "github",
+            "url": "https://github.com/Bitcoin-ABC/bitcoin-abc"
+        },
+        {
+            "name": "twitter",
+            "url": "https://twitter.com/eCashOfficial"
+        },
+        {
+            "name": "reddit",
+            "url": "https://reddit.com/r/ecash"
+        },
+        {
+            "name": "whitepaper",
+            "url": "https://www.bitcoincash.org/bitcoin.pdf"
+        }
+    ]
+}