DOC: minor corrections to README.md (#61)

DOC: minor corrections to README.md

README.md

@@ -12,13 +12,11 @@
 [![pre-commit.ci status](https://results.pre-commit.ci/badge/github/SydneyAstrophotonicInstrumentationLab/AMICAL/master.svg)](https://results.pre-commit.ci/latest/github/SydneyAstrophotonicInstrumentationLab/AMICAL/master)
 
 [![Code style: black](https://img.shields.io/badge/code%20style-black-000000.svg)](https://github.com/psf/black)
-[![Imports:
-isort](https://img.shields.io/badge/%20imports-isort-%231674b1?style=flat&labelColor=ef8336)](https://pycqa.github.io/isort/)
 
 ## Installation
 
 ```shell
-$ python -m pip install amical
+$ python3 -m pip install amical
 ```
 
 ## What can AMICAL do for you ?