Make the copyright file into an ordinary tiddler file

When it was a text file we were relying on boot.js to be able to figure out the correct title. Better to make it explicit
2012-11-12 22:14:55 +00:00 · 2012-11-12 22:14:55 +00:00 · 5e25d9e9c8
commit 5e25d9e9c8
--- a/core/copyright.tid
+++ b/core/copyright.tid
@ -1,3 +1,6 @@
+title: $:/core/copyright.txt
+type: text/plain
+
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