The Stacks project

covering -> open covering

Thanks to Haohao Liu'
https://stacks.math.columbia.edu/tag/01EP#comment-8265

\text{Mod}(R) ---> \text{Mod}_R and similar

Chech complexes of unbounded complexes

This is a bit lame... and proofs still need to be added or fleshed out.

Whitespace changes

Fix references and labels

	Necessary because of addition of new chapter in previous commit.

Latex: get rid of some overfull boxes

	modified:   algebraic.tex
	modified:   chow.tex
	modified:   coherent.tex
	modified:   cohomology.tex
	modified:   constructions.tex
	modified:   descent.tex
	modified:   desirables.tex
	modified:   divisors.tex
	modified:   etale.tex
	modified:   examples-stacks.tex
	modified:   examples.tex
	modified:   exercises.tex
	modified:   fdl.tex
	modified:   homology.tex
	modified:   hypercovering.tex
	modified:   modules.tex
	modified:   morphisms.tex
	modified:   properties.tex
	modified:   schemes.tex
	modified:   simplicial.tex
	modified:   sites.tex
	modified:   spaces.tex
	modified:   topologies.tex
	modified:   varieties.tex

Started tags infrastructure

	new file:   scripts/add_tags.py
	modified:   scripts/functions.py
	new file:   tags/initial_tags
	new file:   tags/tags

Small stuff about cohomology

	modified:   cohomology.tex
	modified:   homology.tex