Fixed 2 typos

ch03.asciidoc

@@ -192,10 +192,10 @@ With such a strong penalty mechanism in place Alice should never purposely publi
 [Note]
 ====
 In Mastering Bitcoin Andreas states it very elegantly:
-A key characteristic of bitcoin is that once a transaction is valid, it remains valid and does not expire. The only way to cancel a transaction is by souble-spending its inputs with another transaction before it was mined. That's why we used timelocks [...] to ensure that more recent commitments could be spent before older commitments were valid. 
+A key characteristic of bitcoin is that once a transaction is valid, it remains valid and does not expire. The only way to cancel a transaction is by double-spending its inputs with another transaction before it was mined. That's why we used timelocks [...] to ensure that more recent commitments could be spent before older commitments were valid. 
 ====
 
-We will now see how such a penality mechanism can be included to the above construction of the commitment transactions.
+We will now see how such a penalty mechanism can be included to the above construction of the commitment transactions.
 Usually the commitment transaction has at least two outputs, one for each partner.
 However a channel partner will encumber their own output with a timelock and a revocation secret.
 The timelock prevents the owner of the output to spend it directly once the commitment transaction was included to a block.

preface.asciidoc

@@ -181,6 +181,7 @@ Following is an alphabetically sorted list of all the GitHub contributors, inclu
 * Darius E. Parvin (@DariusParvin)
 * Doru Muntean (@chriton)
 * Eduardo Lima III (@elima-iii)
+* Emilio Norrmann (@enorrmann)
 * Hatim Boufnichel (@boufni95)
 * Imran Lorgat (@ImranLorgat)
 * Ricardo Marques (@RicardoM17)