update packages

add some docs

Sources/Blockchain/main.swift

@@ -17,16 +17,28 @@ repeat {
     print("Enter command:")
     command = readLine()
     
+    // Create a new block
     if command == "create" {
         print("data for the new block:")
         let data = readLine()
         blockchain.createBlock(data: data ?? "")
     }
     
+    // Create a lot of blocks
     if command == "spam" {
         for _ in 1...1000 {
             blockchain.createBlock(data: "\((blockchain.chain.last?.index ?? 0)+1)")
         }
     }
     
+    // Check validity of the blockchain
+    if command == "validity" {
+        blockchain.chainValidity()
+    }
+    
+    // Insert a corrupted block
+    if command == "corrupt" {
+        blockchain.insertCorruptedBlock()
+    }
+    
 } while command != "exit"