The Stacks project

blow-ups, blow ups, and blowups

THis is made difficult because I can 'blow up' something

Thanks to Antoine Chambert-Loir
https://stacks.math.columbia.edu/tag/01OF#comment-2823

Composition admissible blowups

	This commit also includes some really basic material on relative
	proj which was so far missing from the project. Probably because
	we haven't found a way to present this material in a good way.

Universal property of blowing up

	Seems to be completely general. Also we moved all the material
	on blowups together in a section of divisors.tex which makes a
	lot of sense as the universal property is all about divisors...

Universal property of blowing up

	Seems to be completely general. Also we moved all the material
	on blowups together in a section of divisors.tex which makes a
	lot of sense as the universal property is all about divisors...

Started tags infrastructure

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

Formulation of quasi-coherent sheaf associated to graded module in th
relative setting slightly improved

	modified:   constructions.tex