Remove links in the index

This just duplicate the info in the sidebar, except it's out of date
because no one remembers to add things here. In the future we might try
to automatically generate these links from the sidebar.

Author: smarter

docs/docs/index.md

@@ -10,37 +10,3 @@ The theory behind these constructors is researched in DOT, a calculus for depend
 
 In this documentation you will find information on how to use the Dotty compiler on your machine, navigate through
 the code, setup Dotty with your favorite IDE and more!
-
-Contents
--------
-
-* Dotty Language Reference
-    - [Intersection Types](reference/intersection-types.md)
-    - [Union Types](reference/union-types.md)
-    - [Trait Parameters](reference/trait-parameters.md)
-    - [Enumerations](reference/enums.md)
-    - [Algebraic Data Types](reference/adts.md)
-    - [Enum Translation](reference/desugarEnums.md)
-    - [By-Name Implicits](reference/implicit-by-name-parameters.md)
-* Usage
-    - [Dotty projects with sbt](usage/sbt-projects.md)
-    - [IDE support for Dotty](usage/ide-support.md)
-    - [Dotty projects with cbt](usage/cbt-projects.md)
-* Contributing to Dotty
-    - [Getting Started](contributing/getting-started.md): details on how to run tests, use the cli scripts
-    - [Workflow](contributing/workflow.md): common dev patterns and hints
-    - [Eclipse](contributing/eclipse.md): setting up dev environment
-    - [Intellij-IDEA](contributing/intellij-idea.md)
-    - [Working with the Backend](contributing/backend.md)
-* Internals document the compiler internals
-    - [Syntax Summary](internals/syntax.md): brief analysis of the syntax
-    - [Project Structure](internals/overall-structure.md)
-    - [Backend](internals/backend.md)
-    - [Contexts](internals/contexts.md): details the use of `Context` in the compiler
-    - [Dotty vs Scala 2](internals/dotc-scalac.md): explaining the differences between Scalac and Dotty
-    - [Higher Kinded Type Scheme](internals/higher-kinded-v2.md)
-    - [Periods](internals/periods.md)
-    - [Type System](internals/type-system.md)
-* Resources
-    - [Talks](resources/talks.md): presentations of the various aspects of Dotty
-