The Stacks project

Add a condition

Thanks to Haohao Liu
https://stacks.math.columbia.edu/tag/0010#comment-8681

LaTeX: \Ob

	Introduced a macro

	\def\Ob{\mathop{\rm Ob}\nolimits}

	and replaced any occurence of \text{Ob}( with \Ob(. There are
	still some occurences of \text{Ob} but these are sets, not the
	operator that takes the set of objects of a category.

Sets.tex: mostly editorial

	Thanks to Titus Teodorescu.

Started tags infrastructure

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

Added a lemma stating that in a big abelian category with enough
injectives there are plenty of ``small'' abelian subcategories which
contain enough injectives

	modified:   sets.tex