Documentation appearance rework, pass 1, phase 1: background,

	aligning first H1 and image in the centre.  This is just the
	top-level htdocs/manual directory.  Still to do: subordinate
	directories, format normalisation (to HR or not to HR?).


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@78218 13f79535-47bb-0310-9956-ffa450edef68