[mlir] Add tutorial index.md pages

Sets the content for the section entry pages Hugo side.

Differential Revision: https://reviews.llvm.org/D87969

mlir/docs/Tutorials/Toy/Ch-1.md

@@ -1,43 +1,7 @@
-# Chapter 1: Toy Tutorial Introduction
+# Chapter 1: Toy Language and AST
 
 [TOC]
 
-This tutorial runs through the implementation of a basic toy language on top of
-MLIR. The goal of this tutorial is to introduce the concepts of MLIR; in
-particular, how [dialects](../../LangRef.md#dialects) can help easily support
-language specific constructs and transformations while still offering an easy
-path to lower to LLVM or other codegen infrastructure. This tutorial is based on
-the model of the
-[LLVM Kaleidoscope Tutorial](https://llvm.org/docs/tutorial/MyFirstLanguageFrontend/index.html).
-
-This tutorial assumes you have cloned and built MLIR; if you have not yet done
-so, see
-[Getting started with MLIR](https://mlir.llvm.org/getting_started/).
-
-## The Chapters
-
-This tutorial is divided in the following chapters:
-
--   [Chapter #1](Ch-1.md): Introduction to the Toy language and the definition
-    of its AST.
--   [Chapter #2](Ch-2.md): Traversing the AST to emit a dialect in MLIR,
-    introducing base MLIR concepts. Here we show how to start attaching
-    semantics to our custom operations in MLIR.
--   [Chapter #3](Ch-3.md): High-level language-specific optimization using
-    pattern rewriting system.
--   [Chapter #4](Ch-4.md): Writing generic dialect-independent transformations
-    with Interfaces. Here we will show how to plug dialect specific information
-    into generic transformations like shape inference and inlining.
--   [Chapter #5](Ch-5.md): Partially lowering to lower-level dialects. We'll
-    convert some of our high level language specific semantics towards a generic
-    affine oriented dialect for optimization.
--   [Chapter #6](Ch-6.md): Lowering to LLVM and code generation. Here we'll
-    target LLVM IR for code generation, and detail more of the lowering
-    framework.
--   [Chapter #7](Ch-7.md): Extending Toy: Adding support for a composite type.
-    We'll demonstrate how to add a custom type to MLIR, and how it fits in the
-    existing pipeline.
-
 ## The Language
 
 This tutorial will be illustrated with a toy language that we’ll call “Toy”

mlir/docs/Tutorials/Toy/_index.md

@@ -0,0 +1,37 @@
+# Toy Tutorial
+
+This tutorial runs through the implementation of a basic toy language on top of
+MLIR. The goal of this tutorial is to introduce the concepts of MLIR; in
+particular, how [dialects](../../LangRef.md#dialects) can help easily support
+language specific constructs and transformations while still offering an easy
+path to lower to LLVM or other codegen infrastructure. This tutorial is based on
+the model of the
+[LLVM Kaleidoscope Tutorial](https://llvm.org/docs/tutorial/MyFirstLanguageFrontend/index.html).
+
+This tutorial assumes you have cloned and built MLIR; if you have not yet done
+so, see
+[Getting started with MLIR](https://mlir.llvm.org/getting_started/).
+
+This tutorial is divided in the following chapters:
+
+-   [Chapter #1](Ch-1.md): Introduction to the Toy language and the definition
+    of its AST.
+-   [Chapter #2](Ch-2.md): Traversing the AST to emit a dialect in MLIR,
+    introducing base MLIR concepts. Here we show how to start attaching
+    semantics to our custom operations in MLIR.
+-   [Chapter #3](Ch-3.md): High-level language-specific optimization using
+    pattern rewriting system.
+-   [Chapter #4](Ch-4.md): Writing generic dialect-independent transformations
+    with Interfaces. Here we will show how to plug dialect specific information
+    into generic transformations like shape inference and inlining.
+-   [Chapter #5](Ch-5.md): Partially lowering to lower-level dialects. We'll
+    convert some of our high level language specific semantics towards a generic
+    affine oriented dialect for optimization.
+-   [Chapter #6](Ch-6.md): Lowering to LLVM and code generation. Here we'll
+    target LLVM IR for code generation, and detail more of the lowering
+    framework.
+-   [Chapter #7](Ch-7.md): Extending Toy: Adding support for a composite type.
+    We'll demonstrate how to add a custom type to MLIR, and how it fits in the
+    existing pipeline.
+
+The [first chapter](Ch-1.md) will introduce the Toy language and AST.

mlir/docs/Tutorials/_index.md

@@ -0,0 +1,4 @@
+# Tutorials
+
+This section contains multiple MLIR tutorials.
+See [Toy tutorial](toy) for an introduction to using MLIR infrastructure.