DOC: document the various pitfalls of reading html

DOC: change formatting

DOC: more formatting

DOC: add bold substitutions

DOC: fill out bold links and rephrase

DOC: fill out link to gotchas

DOC: add gigantic install.rst warning

DOC: move version note about html5lib to first mention of it

DOC: add same to readme and add boto to install.rst

DOC: add anaconda note

DOC: add note about debian based system installation

DOC: add correct lexer for pygments formatting of code snippets

DOC: move boto up
Merge pull request #3751 from cpcloud/read-html-bs4-install-docs

DOC: document bs4/lxml/html5lib issues