remove lgtm shield from the README

lgtm service is obsolete now

README.md

@@ -17,7 +17,7 @@ For online access to a selection of package functions see [online Atom Calculato
 
 If you want to contribute to the project, [check this page](https://arc-alkali-rydberg-calculator.readthedocs.io/en/latest/contribute.html).
 
-![Documentation Status](https://readthedocs.org/projects/arc-alkali-rydberg-calculator/badge/?version=latest) [![PyPI Linux](https://github.com/nikolasibalic/ARC-Alkali-Rydberg-Calculator/actions/workflows/pypi_linux.yaml/badge.svg)](https://github.com/nikolasibalic/ARC-Alkali-Rydberg-Calculator/actions/workflows/pypi_linux.yaml) [![PyPI Windows](https://github.com/nikolasibalic/ARC-Alkali-Rydberg-Calculator/actions/workflows/pypi_windows.yaml/badge.svg)](https://github.com/nikolasibalic/ARC-Alkali-Rydberg-Calculator/actions/workflows/pypi_windows.yaml) [![PyPI macos](https://github.com/nikolasibalic/ARC-Alkali-Rydberg-Calculator/actions/workflows/pypi_macos.yaml/badge.svg)](https://github.com/nikolasibalic/ARC-Alkali-Rydberg-Calculator/actions/workflows/pypi_macos.yaml) [![Language grade: Python](https://img.shields.io/lgtm/grade/python/g/nikolasibalic/ARC-Alkali-Rydberg-Calculator.svg?logo=lgtm&logoWidth=18)](https://lgtm.com/projects/g/nikolasibalic/ARC-Alkali-Rydberg-Calculator/context:python) [![PyPI version](https://badge.fury.io/py/ARC-Alkali-Rydberg-Calculator.svg)](https://badge.fury.io/py/ARC-Alkali-Rydberg-Calculator)  [![Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/gh/nikolasibalic/ARC-Alkali-Rydberg-Calculator.git/master?urlpath=lab%2Ftree%2Fdoc%2FRydberg_atoms_a_primer_notebook.ipynb)
+![Documentation Status](https://readthedocs.org/projects/arc-alkali-rydberg-calculator/badge/?version=latest) [![PyPI Linux](https://github.com/nikolasibalic/ARC-Alkali-Rydberg-Calculator/actions/workflows/pypi_linux.yaml/badge.svg)](https://github.com/nikolasibalic/ARC-Alkali-Rydberg-Calculator/actions/workflows/pypi_linux.yaml) [![PyPI Windows](https://github.com/nikolasibalic/ARC-Alkali-Rydberg-Calculator/actions/workflows/pypi_windows.yaml/badge.svg)](https://github.com/nikolasibalic/ARC-Alkali-Rydberg-Calculator/actions/workflows/pypi_windows.yaml) [![PyPI macos](https://github.com/nikolasibalic/ARC-Alkali-Rydberg-Calculator/actions/workflows/pypi_macos.yaml/badge.svg)](https://github.com/nikolasibalic/ARC-Alkali-Rydberg-Calculator/actions/workflows/pypi_macos.yaml) [![PyPI version](https://badge.fury.io/py/ARC-Alkali-Rydberg-Calculator.svg)](https://badge.fury.io/py/ARC-Alkali-Rydberg-Calculator)  [![Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/gh/nikolasibalic/ARC-Alkali-Rydberg-Calculator.git/master?urlpath=lab%2Ftree%2Fdoc%2FRydberg_atoms_a_primer_notebook.ipynb)
 
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