mark ruff as recommended tool

README.md

@@ -323,8 +323,8 @@ Here is an exhaustive list of formatters: <https://github.com/life4/awesome-pyth
 A reasonable selection of tools could be: `flake8` + `black` + `isort`. (That is what we
 have been using in CHIMeRA.)
 
-Alternatively, [`ruff`](https://docs.astral.sh/ruff/) is a new tool that does it all: linting
-and formatting, with sane default settings.
+**Recommendation**: Alternatively, [`ruff`](https://docs.astral.sh/ruff/) is a new tool that does
+it all: linting and formatting, with sane default settings.
 **We will proceed with `ruff` as our only linting and formatting tool.**