Fix formatting in documented copyright, add my own contribution period

alerque · alerque · commit 0068e6fd36fb · 2019-07-01T17:58:25.000+03:00
diff --git a/README.mkd b/README.mkd
@@ -109,7 +109,8 @@ insert the closing bracket after calling the completion, too.
 License
 -------
 
-Copyright 2009-2013 Johann Klähn
+Copyright 2019 Caleb Maclennan  
+Copyright 2009–2017 Johann Klähn  
 Copyright 2009 Stefan Karrmann  
 Copyright 2005 Wolfgang Oertl
 
diff --git a/doc/ledger.txt b/doc/ledger.txt
@@ -396,7 +396,8 @@ LICENSE                                                       *ledger-license*
 
 https://github.com/ledger/vim-ledger
 
-Copyright 2009-2013 Johann Klähn
+Copyright 2019 Caleb Maclennan
+Copyright 2009–2017 Johann Klähn
 Copyright 2009 Stefan Karrmann
 Copyright 2005 Wolfgang Oertl
 
