update installation instructions

docs/installation.md

@@ -2,36 +2,34 @@
 
 ## Required dependencies
 
-- Python (3.11 or later)
-- [cartopy](http://scitools.org.uk/cartopy/) (0.23 or later)
-- [matplotlib](http://matplotlib.org/) (3.9 or later)
-- [numpy](http://www.numpy.org/) (1.26 or later)
-- [xarray](http://xarray.pydata.org/) (2024.7 or later)
+- Python
+- [cartopy](http://scitools.org.uk/cartopy/)
+- [matplotlib](http://matplotlib.org/)
+- [numpy](http://www.numpy.org/)
+- [xarray](http://xarray.pydata.org/)
 
 ## Optional dependencies
 
-- [seaborn](https://seaborn.pydata.org/) (0.13 or later)
+- [seaborn](https://seaborn.pydata.org/)
 
 ## Instructions
 
 ### Install latest released version
 
-mplotutils is now available on PyPi - and can be installed with `pip`:
+mplotutils is available on PyPi and can be installed with `pip`:
 
 ```bash
 python -m pip install mplotutils
 ```
 
-Its not (yet) on conda-forge. To install it into a conda environment, add the required
-dependencies first before using pip to install mplotutils as well:
+mplotutils is available on conda-forge and can be installed with `conda` / `mamba`:
 
 ```bash
-mamba install -c conda-forge cartopy xarray
-python -m pip install mplotutils
+mamba install -c conda-forge mplotutils
 ```
 
 ### Install development version
 
 ```bash
-pip install git+https://github.com/mpytools/mplotutils
+python -m pip install git+https://github.com/mpytools/mplotutils
 ```