Improve installation instructions

[eit-maxlcummins]

installation instructions are clunky - use this instead

# 1. Create & activate a fresh env (if you haven’t already):
mamba create -n bactqc-env python=3.8 -y
mamba activate bactqc-env

# 2. Install the Python deps listed in your README:
pip install pandas requests click rich emoji

#    (Or, if you have a requirements.txt in the repo:
#     pip install -r requirements.txt
#    )

# 3. From the repo root, install bactQC itself:
cd /path/to/bactQC
pip install .

# 4. Verify that the CLI is available:
which bactQC
bactQC --help