docs(README): add ToC.

README.md

@@ -12,6 +12,26 @@ we use mainly in [DataChef](https://datachef.co). However, given the
 open source nature of this project, feel free to challenge these
 decision and help us to improve them.
 
+<!-- markdown-toc start - Don't edit this section. Run M-x markdown-toc-refresh-toc -->
+**Table of Contents**
+
+- [Inception](#inception)
+    - [In Action](#in-action)
+    - [Features](#features)
+        - [Detailed Features](#detailed-features)
+    - [How to Use](#how-to-use)
+        - [Prerequisites](#prerequisites)
+            - [Optional but Suggested](#optional-but-suggested)
+                - [[direnv](https://direnv.net)](#direnvhttpsdirenvnet)
+        - [Initialize a New Project](#initialize-a-new-project)
+    - [Resources](#resources)
+    - [Contributing](#contributing)
+    - [License](#license)
+    - [Acknowledgments](#acknowledgments)
+
+<!-- markdown-toc end -->
+
+
 ## In Action
 
 [![asciicast](https://asciinema.org/a/Mp4w76BgrVcu4hvUR9nbb8EIL.svg)](https://asciinema.org/a/Mp4w76BgrVcu4hvUR9nbb8EIL)