Added Sphinx docs in reStructuredText, with template for nav bar

.gitignore

doc/CHANGES

doc/README

doc/schema-1.0-1.1.sql

doc/schema-1.1-1.2.sql

doc/schema-1.2-1.3.sql

doc/source/_static/gracedb-nav-style.css

doc/source/_templates/layout.html

doc/source/auth.rst

doc/source/conf.py

doc/source/general.rst

doc/source/images/annotations_flow_white.pdf

doc/source/index.rst

doc/source/lvalert.rst

doc/source/lvem.rst

doc/source/models.rst

doc/source/rest.rst

doc/source/web.rst

gracedb/views.py

templates/base.html