Replace dot with colon before code example to be consistent with the other paragraphs

Author: anbj

book/05-distributed-git/sections/contributing.asc

@@ -465,7 +465,7 @@ Fast forward
 1 files changed, 9 insertions(+), 1 deletions(-)
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-Finally, Jessica might want to make a couple minor changes to all that merged content, so she is free to make those changes, commit them to her local `featureA` branch, and push the end result back to the server.
+Finally, Jessica might want to make a couple minor changes to all that merged content, so she is free to make those changes, commit them to her local `featureA` branch, and push the end result back to the server:
 
 [source,console]
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