spec: remove Contents in favor to GitHub's TOC (#549)

doc/spec.md

@@ -52,156 +52,6 @@ is run; there are no sources of random numbers, clocks, or unspecified
 iterators. This makes Starlark suitable for use in applications where
 reproducibility is paramount, such as build tools.
 
-## Contents
-
-<!-- WTF? No automatic TOC? -->
-
-  * [Overview](#overview)
-  * [Contents](#contents)
-  * [Lexical elements](#lexical-elements)
-  * [Data types](#data-types)
-    * [None](#none)
-    * [Booleans](#booleans)
-    * [Integers](#integers)
-    * [Floating-point numbers](#floating-point-numbers)
-    * [Strings](#strings)
-    * [Lists](#lists)
-    * [Tuples](#tuples)
-    * [Dictionaries](#dictionaries)
-    * [Sets](#sets)
-    * [Functions](#functions)
-    * [Built-in functions](#built-in-functions)
-  * [Name binding and variables](#name-binding-and-variables)
-  * [Value concepts](#value-concepts)
-    * [Identity and mutation](#identity-and-mutation)
-    * [Freezing a value](#freezing-a-value)
-    * [Hashing](#hashing)
-    * [Sequence types](#sequence-types)
-    * [Indexing](#indexing)
-  * [Expressions](#expressions)
-    * [Identifiers](#identifiers)
-    * [Literals](#literals)
-    * [Parenthesized expressions](#parenthesized-expressions)
-    * [Dictionary expressions](#dictionary-expressions)
-    * [List expressions](#list-expressions)
-    * [Unary operators](#unary-operators)
-    * [Binary operators](#binary-operators)
-    * [Conditional expressions](#conditional-expressions)
-    * [Comprehensions](#comprehensions)
-    * [Function and method calls](#function-and-method-calls)
-    * [Dot expressions](#dot-expressions)
-    * [Index expressions](#index-expressions)
-    * [Slice expressions](#slice-expressions)
-    * [Lambda expressions](#lambda-expressions)
-  * [Statements](#statements)
-    * [Pass statements](#pass-statements)
-    * [Assignments](#assignments)
-    * [Augmented assignments](#augmented-assignments)
-    * [Function definitions](#function-definitions)
-    * [Return statements](#return-statements)
-    * [Expression statements](#expression-statements)
-    * [If statements](#if-statements)
-    * [For loops](#for-loops)
-    * [Break and Continue](#break-and-continue)
-    * [Load statements](#load-statements)
-  * [Module execution](#module-execution)
-  * [Built-in constants and functions](#built-in-constants-and-functions)
-    * [None](#none)
-    * [True and False](#true-and-false)
-    * [any](#any)
-    * [all](#all)
-    * [bool](#bool)
-    * [chr](#chr)
-    * [dict](#dict)
-    * [dir](#dir)
-    * [enumerate](#enumerate)
-    * [fail](#fail)
-    * [float](#float)
-    * [getattr](#getattr)
-    * [hasattr](#hasattr)
-    * [hash](#hash)
-    * [int](#int)
-    * [len](#len)
-    * [list](#list)
-    * [max](#max)
-    * [min](#min)
-    * [ord](#ord)
-    * [print](#print)
-    * [range](#range)
-    * [repr](#repr)
-    * [reversed](#reversed)
-    * [set](#set)
-    * [sorted](#sorted)
-    * [str](#str)
-    * [tuple](#tuple)
-    * [type](#type)
-    * [zip](#zip)
-  * [Built-in methods](#built-in-methods)
-    * [dict·clear](#dict·clear)
-    * [dict·get](#dict·get)
-    * [dict·items](#dict·items)
-    * [dict·keys](#dict·keys)
-    * [dict·pop](#dict·pop)
-    * [dict·popitem](#dict·popitem)
-    * [dict·setdefault](#dict·setdefault)
-    * [dict·update](#dict·update)
-    * [dict·values](#dict·values)
-    * [list·append](#list·append)
-    * [list·clear](#list·clear)
-    * [list·extend](#list·extend)
-    * [list·index](#list·index)
-    * [list·insert](#list·insert)
-    * [list·pop](#list·pop)
-    * [list·remove](#list·remove)
-    * [set·add](#set·add)
-    * [set·clear](#set·clear)
-    * [set·difference](#set·difference)
-    * [set·discard](#set·discard)
-    * [set·intersection](#set·intersection)
-    * [set·issubset](#set·issubset)
-    * [set·issuperset](#set·issuperset)
-    * [set·pop](#set·pop)
-    * [set·remove](#set·remove)
-    * [set·symmetric_difference](#set·symmetric_difference)
-    * [set·union](#set·union)
-    * [string·capitalize](#string·capitalize)
-    * [string·codepoint_ords](#string·codepoint_ords)
-    * [string·codepoints](#string·codepoints)
-    * [string·count](#string·count)
-    * [string·elem_ords](#string·elem_ords)
-    * [string·elems](#string·elems)
-    * [string·endswith](#string·endswith)
-    * [string·find](#string·find)
-    * [string·format](#string·format)
-    * [string·index](#string·index)
-    * [string·isalnum](#string·isalnum)
-    * [string·isalpha](#string·isalpha)
-    * [string·isdigit](#string·isdigit)
-    * [string·islower](#string·islower)
-    * [string·isspace](#string·isspace)
-    * [string·istitle](#string·istitle)
-    * [string·isupper](#string·isupper)
-    * [string·join](#string·join)
-    * [string·lower](#string·lower)
-    * [string·lstrip](#string·lstrip)
-    * [string·partition](#string·partition)
-    * [string·removeprefix](#string·removeprefix)
-    * [string·removesuffix](#string·removesuffix)
-    * [string·replace](#string·replace)
-    * [string·rfind](#string·rfind)
-    * [string·rindex](#string·rindex)
-    * [string·rpartition](#string·rpartition)
-    * [string·rsplit](#string·rsplit)
-    * [string·rstrip](#string·rstrip)
-    * [string·split](#string·split)
-    * [string·splitlines](#string·splitlines)
-    * [string·startswith](#string·startswith)
-    * [string·strip](#string·strip)
-    * [string·title](#string·title)
-    * [string·upper](#string·upper)
-  * [Dialect differences](#dialect-differences)
-
-
 ## Lexical elements
 
 A Starlark program consists of one or more modules.