Update README to reflect the latest situation (#2377)

Signed-off-by: Masanori Ogino <[email protected]>

Author: omasanori

README.md

@@ -2,13 +2,13 @@
 
 [![RISC-V ISA Build](https://github.com/riscv/riscv-isa-manual/actions/workflows/isa-build.yml/badge.svg)](https://github.com/riscv/riscv-isa-manual/actions/workflows/isa-build.yml)
 
-This repository contains the source files for the RISC-V Instruction Set Manual, which consists of the Privileged RISC-V Instruction Set Manual (LaTeX) and the Unprivileged RISC-V Instruction Set Manual (AsciiDoc). The preface of each document indicates the version of each standard that has been formally ratified by RISC-V International.
+This repository contains the source files for the RISC-V Instruction Set Manual, which consists of the Unprivileged and Privileged volumes. The preface of each document indicates the version of each standard that has been formally ratified by RISC-V International.
 
 This work is licensed under a [Creative Commons Attribution 4.0 International License](https://creativecommons.org/licenses/by/4.0/). See the [LICENSE](LICENSE) file for details.
 
 The RISC-V Instruction Set Manual is organized into the following volumes:
 
-- Volume I: User-Level ISA
+- Volume I: Unprivileged Architecture
 - Volume II: Privileged Architecture
 
 ## Official and Draft Versions