Fix broken links in docs

Author: peterzhu2118

doc/optparse/creates_option.rdoc

@@ -1,7 +1,7 @@
 Creates an option from the given parameters +params+.
-See {Parameters for New Options}[./option_params.rdoc].
+See {Parameters for New Options}[optparse/option_params.rdoc].
 
 The block, if given, is the handler for the created option.
 When the option is encountered during command-line parsing,
 the block is called with the argument given for the option, if any.
-See {Option Handlers}[./option_params.rdoc#label-Option+Handlers].
+See {Option Handlers}[optparse/option_params.rdoc#label-Option+Handlers].

doc/optparse/tutorial.rdoc

@@ -657,7 +657,7 @@ Though you may never need to call it directly,
 here's the core method for defining an option:
 
 - \Method \OptionParser#make_switch accepts an array of parameters and a block.
-  See {Parameters for New Options}[./option_params.rdoc].
+  See {Parameters for New Options}[optparse/option_params.rdoc].
   This method is unlike others here in that it:
   - Accepts an <em>array of parameters</em>;
     others accept a <em>sequence of parameter arguments</em>.