Refactor specs repo (#87)

* Move VM specs to a VM directory.
* Refactor readme.

Author: adlerjohn

README.md

@@ -1,13 +1,15 @@
-# Fuel Virtual Machine (FuelVM) Specifications
+# Fuel Specifications
 
-This repository specifies the Fuel Virtual Machine (FuelVM), a next-generation verifiable virtual machine for [the Fuel blockchain](https://github.com/FuelLabs).
+This repository specifies the Fuel v2 system, including the Fuel Virtual Machine (FuelVM, FVM), a next-generation verifiable virtual machine for [the Fuel v2 blockchain](https://github.com/FuelLabs).
 
 - [Specification](#specification)
+    - [FuelVM](#fuelvm)
 
 ## Specification
 
+### FuelVM
 The specification is laid out as follows:
-1. [main.md](./specs/main.md): Entry point for reading the specification. Describes the FuelVM at a high level, from its architecture to how it is initialized.
-1. [opcodes.md](./specs/opcodes.md): Defines all opcodes available in the FuelVM.
-1. [tx_format.md](./specs/tx_format.md): Transaction format.
-1. [tx_validity.md](./specs/tx_validity.md): Defines transaction validity rules.
+1. [main.md](./specs/vm/main.md): Entry point for reading the specification. Describes the FuelVM at a high level, from its architecture to how it is initialized.
+1. [opcodes.md](./specs/vm/opcodes.md): Defines all opcodes available in the FuelVM.
+1. [tx_format.md](./specs/vm/tx_format.md): Transaction format.
+1. [tx_validity.md](./specs/vm/tx_validity.md): Defines transaction validity rules.