trivial: fixed spelling

ch03.asciidoc

@@ -71,8 +71,8 @@ Payment channels have a couple of very interesting and useful properties.
 * As the time to update the channel is the only bound, making a payment within a payment channel is almost instant.
 
 Bitcoin had to be about 5 years old until talented developers figured out how payment channels could be constructed and by now there are at least 3 different constructions known.
-This chapter will only focus on the "Poon, Drayja" - Construction since it is actually being used in the Lightning Network and was first described in the Lightning Network whitepaper.
-The other two constructions are the Duplex Micropayment channels which have been introduced by Christian Decker around the same time as the "Poon, Drayja" - channels and the "eltoo" - channels which have been introduced in 2018 by Christian Decker, Rusty Russel and our co-author Olaoluwa Osuntokun.
+This chapter will only focus on the "Poon, Dryja" - Construction since it is actually being used in the Lightning Network and was first described in the Lightning Network whitepaper.
+The other two constructions are the Duplex Micropayment channels which have been introduced by Christian Decker around the same time as the "Poon, Dryja" - channels and the "eltoo" - channels which have been introduced in 2018 by Christian Decker, Rusty Russel and our co-author Olaoluwa Osuntokun.
 The later seem much easier to implement and to have a couple of nicer properties.
 However they need a new OP_CODE to the Bitcoin scripting language and can currently not be implemented on top of the bitcoin mainnet.