CH12: introduce the term "subsidy"

ch10.asciidoc

@@ -94,9 +94,9 @@ transactions.
 and fees")))((("Proof-of-Work algorithm")))((("mining and consensus",
 "Proof-of-Work algorithm")))Miners receive two types of rewards in
 return for the security provided by mining: new coins created with each
-new block, and transaction fees from all the transactions included in
 the block. To earn this reward, miners compete to solve a difficult
 mathematical problem based on a cryptographic hash algorithm. The
+new block (called the _subsidy_), and transaction fees from all the transactions included in
 solution to the problem, called the Proof-of-Work, is included in the
 new block and acts as proof that the miner expended significant
 computing effort. The competition to solve the Proof-of-Work algorithm