Table of Contents with only 2 levels

[AndreaIdini]

The table of contents has only two levels instead of several:

- [A Thesis in theoretical physics](#a-thesis-in-theoretical-physics)
  - [Context](#context)
  - [Reading](#reading)
    - [Bibliographic Research](#bibliographic-research)
    - [Textbook, journals and articles](#textbook-journals-and-articles)
    - [Bibliographic Tools](#bibliographic-tools)
  - [Working](#working)
    - [Programming](#programming)
  - [Writing](#writing)
    - [Scope, Tone, Language](#scope-tone-language)
    - [Constrains](#constrains)
    - [Structure](#structure)
    - [Tools](#tools)
  - [Presenting](#presenting)
  - [Following up](#following-up)