Added .gitignore and removed files that should be ignored

.gitignore

.vscode/settings.json

docs/build/.buildinfo

docs/build/.doctrees/environment.pickle

docs/build/.doctrees/example.doctree

docs/build/.doctrees/index.doctree

docs/build/.doctrees/src.doctree

docs/build/_images/TernaryConcentrations.svg

docs/build/_images/TernaryPotential.svg

docs/build/_images/TernaryPressure.svg

docs/build/_sources/example.rst.txt

docs/build/_sources/index.rst.txt

docs/build/_sources/src.rst.txt

docs/build/_static/_sphinx_javascript_frameworks_compat.js

docs/build/_static/basic.css

docs/build/_static/check-solid.svg

docs/build/_static/clipboard.min.js

docs/build/_static/copy-button.svg

docs/build/_static/copybutton.css

docs/build/_static/copybutton.js