doc: unify headers

[monperrus]

Unify documentation headers to achieve a beautiful table of contents

• Introduction
• Getting started
  • Core concepts
    • Abstract Syntax Tree
    • Code Analysis
    • Code Transformation
  • Using Spoon for Architecture Enforcement
    • Example rule: never use the TreeSet constructor
    • Example rule: all test classes must start or end with "Test"
    • Example rule: all public methods must be documented
    • Related work in architecture enforcement
  • Using Spoon as a Better Runtime Reflection API
  • More about Spoon Processors
    • Examples of Analysis Processors
    • Parallel Processor
  • FAQ
    • Where is the Javadoc?
    • Are there snapshots versions deployed somewhere?
    • How to access Spoon's source code repository?
    • What is the meaning of each digit in the version X.Y.Z of spoon?
    • Where is the Spoon metamodel?
    • How to prevent Annotation processors from consuming the annotations that they process?
    • How to compare and create type references in a type-safe way?
    • How to set the JDT compiler arguments?
• Querying source code elements
  • Navigation and Query
    • Getters
    • Filters
    • Scanners
    • Iterator
    • Queries
  • Path
    • Evaluating AST paths
    • Creating AST paths
      • From an existing element
      • From a string
      • From the API
  • Matching elements
  • Spoon Patterns
    • Example usage
    • PatternBuilder
    • Pattern
    • Match
    • PatternBuilderHelper
    • PatternParameterConfigurator
    • InlinedStatementConfigurator
    • Generator
    • Notes on patterns
• Code Transformation
  • Transformation processors
    • Factories and setters to create AST elements
    • Refactoring transformations
  • Examples of Spoon Transformation Usages
    • Transformation with API
    • Transformation with Annotations
    • Transformation with Templates
    • Transformation with Patterns
  • Processor for annotations
    • Annotation Processing Example
    • The Annotation Processor Interface
  • Transformation with Templates
    • Definition of templates
    • Template Instantiation
    • Kinds of templating
      • Subclassing
      • StatementTemplate
      • Subclassing
      • BlockTemplate
      • Subclassing
      • ExpressionTemplate
      • Subclassing
      • ExtensionTemplate
    • Template parameters
      • AST elements
      • Literal template Parameters
      • Inlining foreach expressions
  • Testing code transformations
    • The Assert class
    • Assertion Types
    • Assertion example
• Usage
  • Using Spoon as a Java library
    • The Launcher class
    • Pretty-printing modes
    • The MavenLauncher class
    • Analyzing bytecode with JarLauncher
    • Resolution of elements and classpath
  • Declaring the dependency to Spoon
    • Maven
    • Gradle
  • Advanced launchers
    • Incremental Launcher
    • Fluent LauncherAPI
  • Using Spoon from the Command Line
  • Using Spoon from Maven
  • Using Spoon from Gradle
• Spoon Meta model
  • Structural elements
  • Code elements
    • CtArrayRead
    • CtArrayWrite
    • CtAssert
    • CtAssignment
    • CtBinaryOperator
    • CtBlock
    • CtBreak
    • CtCase
    • CtConditional
    • CtConstructorCall
    • CtContinue
    • CtDo
    • CtExecutableReferenceExpression
    • CtFieldRead
    • CtFieldWrite
    • CtFor
    • CtForEach
    • CtIf
    • CtInvocation
    • CtJavaDoc
    • CtLambda
    • CtLiteral
    • CtLocalVariable
    • CtNewArray
    • CtNewClass
    • CtOperatorAssignment
    • CtReturn
    • CtSuperAccess
    • CtSwitch
    • CtSwitchExpression
    • CtSynchronized
    • CtThisAccess
    • CtThrow
    • CtTry
    • CtTryWithResource
    • CtTypeAccess
    • CtUnaryOperator
    • CtVariableRead
    • CtVariableWrite
    • CtWhile
    • CtYieldStatement
    • CtAnnotation
    • CtClass
  • References
    • How are references resolved?
    • Do targets of references have to exist before you can reference them?
    • How does this limit transforming code?
  • Creating AST elements
    • Create elements with factories
    • Generating Spoon code for an element
  • Comments and position
    • Javadoc Comments
    • Comment Attribution
    • Processing Comments
    • Source Positions

[nharrand]

LGTM. Shall I merge?

[monperrus]

yes, it's ready!