README: Change grouping of install instructions

Signed-off-by: Alistair Francis <[email protected]>

Author: alistair23

README.md

@@ -37,58 +37,35 @@ Prerequisites
 
     1. Cross compiler for embedded targets
 
-        *ARM*
-
-        You will need an `arm-none-eabi` toolchain for Cortex-M targets.
-
-        **MacOS**:
-        ```
-        $ brew tap ARMmbed/homebrew-formulae && brew update && brew install arm-none-eabi-gcc
-        ```
-
-        **Ubuntu (18.04LTS or later)**:
-        ```
-        $ sudo apt install gcc-arm-none-eabi
-        ```
-
-        **Arch**:
-        ```
-        $ sudo pacman -Syu arm-none-eabi-gcc
-        ```
-
-        **Fedora**:
-        ```
-        $ sudo dnf install arm-none-eabi-gcc-cs
-        ```
-
-        *RISC-V*
-
-        You will need a RISC-V toolchain that supports rv32 targets (64 bit
-        toolchains support rv32 if compiled with multilib support).
-        Some toolchains that can work:
-        - riscv64-none-elf
-        - riscv32-none-elf
-        - riscv64-elf
-        - riscv64-unknown-elf
-        - riscv32-unknown-elf
-
         **MacOS**:
 
         ```shell
+        $ brew tap ARMmbed/homebrew-formulae && brew update && brew install arm-none-eabi-gcc
         $ brew tap riscv/riscv && brew update && brew install riscv-gnu-toolchain
         ```
 
         **Ubuntu (21.10 or later) or Debian (11 or later)**:
 
         ```shell
+        $ sudo apt install gcc-arm-none-eabi
         $ sudo apt install gcc-riscv64-unknown-elf
         ```
 
         **Arch**:
+
         ```shell
+        $ sudo pacman -Syu arm-none-eabi-gcc
         $ sudo pacman -Syu riscv64-elf-gcc
         ```
 
+        **Fedora**:
+
+        NOTE: Fedora currently doesn't have RISC-V support
+
+        ```shell
+        $ sudo dnf install arm-none-eabi-gcc-cs
+        ```
+
         **Other distros**:
 
         If your distro doesn't provide a RISC-V toolchain you can build one yourself
@@ -100,36 +77,26 @@ Prerequisites
 
     1. libc for embedded targets
 
-        *ARM*
-
         **Ubuntu (21.10 or later) or Debian (11 or later)**:
 
+        Use picolibc instead of newlib
+
         ```shell
         $ sudo apt install picolibc-arm-unknown-elf libnewlib-arm-none-eabi
+        $ sudo apt install picolibc-riscv64-unknown-elf
         ```
 
         **Arch**:
-        ```
+
+        ```shell
         $ sudo pacman -Syu arm-none-eabi-newlib
+        $ sudo pacman -Syu riscv32-elf-newlib
         ```
 
         **Fedora**:
-        ```
-        $ sudo dnf install arm-none-eabi-newlib
-        ```
-
-        *RISC-V*
-
-        **Ubuntu (21.10 or later) or Debian (11 or later)**:
-
-        Use picolibc instead of newlib
 
         ```shell
-        $ sudo apt install picolibc-riscv64-unknown-elf
-        ```
-        **Arch**:
-        ```shell
-        $ sudo pacman -Syu riscv32-elf-newlib
+        $ sudo dnf install arm-none-eabi-newlib
         ```
 
         *newlib-nano*