The page main tab

For most pages this tab is suffisent. Subclasses can add more tabs.

Property definitions

	# The page main tab
	#
	# For most pages this tab is suffisent.
	# Subclasses can add more tabs.
	var main_tab = new DocTab("main", "Main")

src/doc/static/static_base.nit:105,2--109,42

	# For mentities the main tab is the doc tab
	redef var main_tab = new DocTab("doc", "Doc", true, "book")

src/doc/static/static_base.nit:147,2--148,60