Update preface.asciidoc

bitcoin address clearer explanation

preface.asciidoc

@@ -115,7 +115,7 @@ address (aka public key)::
 ((("bitcoin address")))
 ((("address", see="bitcoin address")))
 ((("public key", see="bitcoin address")))
-	A bitcoin address looks like +1DSrfJdB2AnWaFNgSbv3MZC2m74996JafV+, they always start with a one. You can have as many as you like, share them so people can send you coins.
+	A bitcoin address looks like +1DSrfJdB2AnWaFNgSbv3MZC2m74996JafV+, they always start with a one. Just like you ask others to send an email to your email address, you would ask others to send you bitcoin to your bitcoin address.
 
 bitcoin::
 ((("bitcoin"))) 
@@ -198,25 +198,25 @@ Many contributors offered comments, corrections and additions to the early-relea
 
 ===== (Name - Github ID)
 
-* *Minh T. Nguyen - enderminh: Github contribution editor*
-* Ed Eykholt - edeykholt
+* *Minh T. Nguyen - enderminh: Github contribution editor*
+* Ed Eykholt - edeykholt
 * Michalis Kargakis - kargakis
-* Erik Wahlström - erikwam
+* Erik Wahlström - erikwam
 * Richard Kiss - richardkiss
 * Eric Winchell - winchell
 * Sergej Kotliar - ziggamon
-* Nagaraj Hubli - nagarajhubli
-* ethers
+* Nagaraj Hubli - nagarajhubli
+* ethers
 * Alex Waters - alexwaters
-* Mihail Russu - MihailRussu
+* Mihail Russu - MihailRussu
 * Ish Ot Jr. - ishotjr
 * James Addison - jayaddison
-* Nekomata - nekomata-3
-* Simon de la Rouviere - simondlr
-* Chapman Shoop - belovachap
-* Holger Schinzel - schinzelh
+* Nekomata - nekomata-3
+* Simon de la Rouviere - simondlr
+* Chapman Shoop - belovachap
+* Holger Schinzel - schinzelh
 * effectsToCause - vericoin
-* Stephan Oeste - Emzy
-* Joe Bauers - joebauers
-* Jason Bisterfeldt - jbisterfeldt
+* Stephan Oeste - Emzy
+* Joe Bauers - joebauers
+* Jason Bisterfeldt - jbisterfeldt
 * Ed Leafe - EdLeafe