Grammar fuzzing knowledge

Currently we do not have any grammar fuzzing chapters. It's a big part of fuzzing and has be proven to find many bugs int he past. I can help redacting this chapter if anyone is down.

We should especially mention the followings tools:

Grimoir - Coverage-guided fuzzing that learns structure while fuzzing (no grammar required)
Nautilus - Coverage-guided fuzzing with a user-provided grammar (classic “grammar + coverage feedback”)
Gramatron - Coverage-guided grammar-aware fuzzing, but instead of directly mutating parse trees it uses grammar automatons
Autarkie - Instant grammar fuzzing in Rust: the grammar is defined in Rust code and a fuzzer is (mostly) generated for you using procedural macros
Gramarimator - A grammar-based generator/fuzzer built around ANTLR v4 grammars
Fandango - A specification-driven fuzzer/generator where the spec is grammar + constraints.

Nautilus and Fandango are IMO the most important of the list.

Most of them can be plugged into LibAFL.

Start by reviewing the handbook's existing fuzzing chapters and determine where a grammar fuzzing chapter belongs; no file or entry point is named in the issue. Cover grammar fuzzing with particular attention to Nautilus and Fandango, include the other listed tools, and explain how they relate to LibAFL. Done means the chapter is integrated into the handbook and accurately describes the tools.