Update README.rdoc

* Removed mentioning of ruby 1.8 now Ruby 2.5 is the minimum version
* Updated link at the top to point to github
* For bugs mention github issues

README.rdoc

@@ -1,17 +1,12 @@
 = Racc
 
-* http://i.loveruby.net/en/projects/racc/
+* https://github.com/ruby/racc
 
 == DESCRIPTION:
 
   Racc is a LALR(1) parser generator.
   It is written in Ruby itself, and generates Ruby program.
 
-  NOTE: Ruby 1.8.x comes with Racc runtime module.  You
-  can run your parsers generated by racc 1.4.x out of the
-  box.
-
-
 == Requirement
 
   *  Ruby 2.5 or later.
@@ -74,7 +69,8 @@
 == Bug Reports
 
   Any kind of bug report is welcome.
-  If you find a bug of Racc, please email me. Your grammar file,
+  If you find a bug of Racc, please report an issue at 
+  https://github.com/ruby/racc/issues. Your grammar file,
   debug output generated by "racc -g", are helpful.