docs: Include linter requirements in README setup instructions

Added isort, black, and flake8 to Python setup steps and mentioned Verible as a dependency for RTL linting.

Signed-off-by: Miguel Osorio <miguelosorio@google.com>

Author: moidx

README.md

@@ -43,6 +43,7 @@ Files under the [tools](tools/) directory may be available under a different lic
 - Verilator **(4.106 or later)** must be installed on the system if running with Verilator
 - If adding/removing instructions, [`espresso`](https://github.com/chipsalliance/espresso/tree/master) must be installed (used by `tools/coredecode`). Remember to checkout on `3.x` branch.
 - RISCV tool chain (based on gcc version 8.3 or higher) must be installed so that it can be used to prepare RISCV binaries to run.
+- [**Verible**](https://github.com/chipsalliance/verible) is used for SystemVerilog linting and formatting.
 - **Python 3.10+** is required for verification, documentation, and linting.
 
 ### Python Environment Setup
@@ -61,7 +62,7 @@ source .venv/bin/activate
 pip install -r verification/top/requirements.txt \
             -r verification/block/requirements.txt \
             -r docs/requirements.txt \
-            nox meson
+            nox meson isort black flake8
 ```
 
 #### Using `Conda`
@@ -76,7 +77,7 @@ conda activate veer-el2
 pip install -r verification/top/requirements.txt \
             -r verification/block/requirements.txt \
             -r docs/requirements.txt \
-            nox meson
+            nox meson isort black flake8
 ```
 
 ## Quickstart guide