doc: fix mention of availability (mpytools#154)

Author: mathause

docs/installation.md

@@ -14,25 +14,22 @@
 
 ## Instructions
 
-mplotutils itself is a pure Python package, but its dependencies are not.
-The easiest way to get them installed is to use [conda](http://conda.io/) or [mamba](https://mamba.readthedocs.io/en/latest/).
+### Install latest released version
+
+mplotutils is now available on PyPi - and can be installed with `pip`:
 
 ```bash
-mamba install -c conda-forge cartopy xarray
+python -m pip install mplotutils
 ```
 
-mplotutils is not available from pypi or conda-forge, therefore it needs to be installed using pip directly from github.
-
-
-### Install latest released version
-
-mplotutils is now available on PyPi - install it with `pip`:
+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:
 
 ```bash
+mamba install -c conda-forge cartopy xarray
 python -m pip install mplotutils
 ```
 
-
 ### Install development version
 
 ```bash