Update table of contents.

Author: m-voit

study-project/paper.md

@@ -12,17 +12,17 @@ At the end of the paper there will be an evaluation and summary on how suitable
 1. [JavaScript Overview](#javascript-overview)
 1. [Parser for Boolean expressions](#parser-for-boolean-expressions)
 1. [Functional programming concepts](#functional-programming-concepts)
-  1. [Type system](#type-system)
-  1. [Immutability](#immutability)
-  1. [First-class functions](#first-class-functions)
-  1. [Closures and lambda expressions](#closures-and-lambda-expressions)
-  1. [Higher-order functions](#higher-order-functions)
-  1. [Function composition](#function-composition)
-  1. [Pure functions](#pure-functions)
-  1. [Lazy evaluation](#lazy-evaluation)
-  1. [Recursion and tail-call optimization](#recursion-and-tail-call-optimization)
-  1. [Algebraic data types](#algebraic-data-types)
-  1. [Pattern matching](#pattern-matching)
+    1. [Type system](#type-system)
+    1. [Immutability](#immutability)
+    1. [First-class functions](#first-class-functions)
+    1. [Closures and lambda expressions](#closures-and-lambda-expressions)
+    1. [Higher-order functions](#higher-order-functions)
+    1. [Function composition](#function-composition)
+    1. [Pure functions](#pure-functions)
+    1. [Lazy evaluation](#lazy-evaluation)
+    1. [Recursion and tail-call optimization](#recursion-and-tail-call-optimization)
+    1. [Algebraic data types](#algebraic-data-types)
+    1. [Pattern matching](#pattern-matching)
 1. [Summary](#summary)
 1. [References](#references)