Data classes and other retrofit logic added

app/src/main/java/ru/vendetti/bitcoin_summarizer/GlobalResponse.kt

@@ -0,0 +1,15 @@
+package ru.vendetti.bitcoin_summarizer
+
+import com.google.gson.annotations.SerializedName
+
+// Обёртка для данных
+data class GlobalResponse(
+    val data: GlobalData
+)
+
+// Сами данные
+data class GlobalData(
+    @SerializedName("active_cryptocurrencies") val activeCryptocurrencies: String,
+    @SerializedName("total_market_cap_usd") val totalMarketCapUsd: String,
+    @SerializedName("total_24h_volume_usd") val total24hVolumeUsd: String
+)