adjust heading depth of theory section
minor
Merge branch 'master' of github.com:ravendb/docs
Merge branch 'generatePDFDoc' of github.com:dominiqueplante/docs

Conflicts:
	version_2_5/docs/Theory/document-key-generation.markdown
	version_2_5/docs/Theory/document-structure-design.markdown
	version_2_5/docs/Theory/ravendb-collections.markdown