Add accessibility attibute in a_img.

[leovalais]

html_of_wiki/src/links.ml

Lines 47 to 53 in 8f562ae

	let img_link contents = function
	| [Some src] ->
	let file = Global.current_file () in
	let root, images = Global.(root (), the_images ()) in
	let uri = Paths.(rewind root file +/+ images +/+ src) in
	let alt = Filename.basename src in
	Lwt.return [Html.img ~src:uri ~alt ()]

The Html.img's alt attribute is set to the filename instead of the content's text.