Merge branch 'nifty_website' into 'NIFTy_8'

Dockerfile

README.md

docs/generate.sh

docs/source/conf.py

docs/source/user/citations.rst

docs/source/user/index.rst

...source/user/niftyre_getting_started_4_CorrelatedFields.py

docs/source/user/old_nifty.rst

docs/source/user/paper.bib

docs/source/user/paper.md

docs/source/user/paper.rst

src/re/evidence_lower_bound.py