replaced long strings of = in LICENSE-CC-BY for git-friendliness

Author: BartMassey

mdbook/src/appendix/4-licenses-and-attribution/LICENSE-CC-BY

@@ -1,6 +1,6 @@
 Attribution 4.0 International
 
-=======================================================================
+---
 
 Creative Commons Corporation ("Creative Commons") is not a law firm and
 does not provide legal services or legal advice. Distribution of
@@ -52,7 +52,7 @@ exhaustive, and do not form part of our licenses.
      for the public:
 	wiki.creativecommons.org/Considerations_for_licensees
 
-=======================================================================
+---
 
 Creative Commons Attribution 4.0 International Public License
 
@@ -373,7 +373,7 @@ Section 8 -- Interpretation.
      processes of any jurisdiction or authority.
 
 
-=======================================================================
+---
 
 Creative Commons is not a party to its public
 licenses. Notwithstanding, Creative Commons may elect to apply one of
@@ -392,4 +392,4 @@ understandings, or agreements concerning use of licensed material. For
 the avoidance of doubt, this paragraph does not form part of the
 public licenses.
 
-Creative Commons may be contacted at creativecommons.org.
+Creative Commons may be contacted at creativecommons.org.