[mlir][docs] Remove the MLIR prefix from several titles.

This prefix is already implied by the doc location and functions only as
filler.

mlir/docs/GenericDAGRewriter.md

@@ -1,4 +1,4 @@
-# MLIR Generic DAG Rewriter Infrastructure
+# Generic DAG Rewriter Infrastructure
 
 ## Introduction and Motivation
 

mlir/docs/Interfaces.md

@@ -1,4 +1,4 @@
-# MLIR Interfaces
+# Interfaces
 
 MLIR is generic and very extensible; it allows for opaquely representing many
 different dialects that have their own operations, attributes, types, and so on.

mlir/docs/Passes.md

@@ -1,4 +1,4 @@
-# MLIR Passes
+# Passes
 
 This document describes the available MLIR passes and their contracts.
 

mlir/docs/Quantization.md

@@ -1,4 +1,4 @@
-# MLIR Quantization
+# Quantization
 
 This document outlines the design of the MLIR quantization system. While the
 term "quantization" is highly overloaded, in this case, it refers to a fairly

mlir/docs/Traits.md

@@ -1,4 +1,4 @@
-# MLIR Operation Traits
+# Operation Traits
 
 [TOC]