Minor prereq typo, formatting fixes

Signed-off-by: Alex Coles <alex@alexbcoles.com>

data/speakers.yaml

@@ -674,7 +674,7 @@
     use of more advanced bits of the Routing DSL to tame your routes.rb,
     remove your routing stress, and reduce the chance of being eaten by a Grue.
 
-    *Prerequisites* - Rails 3.2 and bundler must be available on your laptop.
+    *Prerequisites* - Rails 3.2 and Bundler must be available on your laptop.
 -
   name:         Dirkjan Bussink
   company:      Nedap
@@ -702,7 +702,7 @@
     as GDB, the Rubinius disassembler and others to investigate and fix this
     issue.
 
-    *Prerequisites* - http://2012.eurucamp.org/2012/08/14/rubinius-workshop-preparation
+    *Prerequisites* - <http://2012.eurucamp.org/2012/08/14/rubinius-workshop-preparation>
 -
   name:         Andrzej Krzywda
   twitter:      andrzejkrzywda
@@ -736,7 +736,7 @@
     DCI, the new hotness in the Rails world, can work even better on the frontend
     and AOP can be really helpful in the Model Gui communication.
 
-    *Prerequisites* - https://gist.github.com/3353574
+    *Prerequisites* - <https://gist.github.com/3353574>
 -
   name:         Sebastian Burkhart & Dirk Holzapfel
   twitter:      bitcrowd
@@ -756,13 +756,14 @@
     Bring your laptops and hack with us. We'll build a simple CRUD app with
     2 connected models and authentication.
 
-    *Prerequsites* - you should have at least medium skills in Rails and
-    CoffeScript to enjoy the session; please check out the Github repo
+    *Prerequisites* - you should have at least medium skills in Rails and
+    CoffeScript to enjoy the session; please check out the GitHub repo
     mentioned below and make sure you have Ruby 1.9.3 installed.
 
     Sources:
-    * http://joosy.ws
-    * https://github.com/dirkholzapfel/joosy-awesome-icons
+
+    * <http://joosy.ws>
+    * <https://github.com/dirkholzapfel/joosy-awesome-icons>
 -
   name:         Florian Plank
   twitter:      polarblau