Switch license to BSD-3-Clause

The theme is based on Darkfish, so it must keep the same license.

LICENSE

@@ -0,0 +1,29 @@
+RorVsWild RDoc theme is based on Darkfish, of which this is the original license:
+
+
+Copyright (c) 2007, 2008, Michael Granger. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+* Redistributions of source code must retain the above copyright notice,
+  this list of conditions and the following disclaimer.
+
+* Redistributions in binary form must reproduce the above copyright notice,
+  this list of conditions and the following disclaimer in the documentation
+  and/or other materials provided with the distribution.
+
+* Neither the name of the author/s, nor the names of the project's
+  contributors may be used to endorse or promote products derived from this
+  software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

rorvswild_theme_rdoc.gemspec

@@ -10,8 +10,8 @@ Gem::Specification.new do |s|
   s.summary = " RDoc theme for developers with sensitive eyes."
   s.homepage = "https://github.com/BaseSecrete/rorvswild-theme-rdoc"
   s.email = ""
-  s.license = "MIT"
+  s.license = "BSD-3-Clause"
 
   s.require_path = "lib"
-  s.files = Dir["lib/**/*", "README.md"]
+  s.files = Dir["lib/**/*", "README.md", "LICENSE"]
 end