Add difficulty adjustment endpoints methods.

src/interfaces/bitcoin/difficulty.ts

@@ -0,0 +1,13 @@
+
+export interface Adjustment {
+  progressPercent: number,
+  difficultyChange: number,
+  estimatedRetargetDate: number,
+  remainingBlocks: number,
+  remainingTime: number,
+  previousRetarget: number,
+}
+
+export interface DifficultyInstance {
+  getDifficultyAdjustment: () => Promise<Adjustment>;
+}

src/interfaces/index.ts

@@ -1,5 +1,6 @@
 import { AddressInstance } from './bitcoin/addresses';
 import { BlockInstance } from './bitcoin/blocks';
+import { DifficultyInstance } from './bitcoin/difficulty';
 import { FeeInstance } from './bitcoin/fees';
 import { MempoolInstance } from './bitcoin/mempool';
 import { TxInstance } from './bitcoin/transactions';
@@ -21,6 +22,7 @@ export interface MempoolReturn {
   bitcoin: {
     addresses: AddressInstance;
     blocks: BlockInstance;
+    difficulty: DifficultyInstance;
     fees: FeeInstance;
     mempool: MempoolInstance;
     transactions: TxInstance;