feat: denote directory support

autoload/denote/completion.vim

@@ -24,7 +24,7 @@ endfunction
 " Return completion items given by the base
 function s:suggestions(base)
 	let prefix = a:base->matchstr('^denote:\zs.*$')
-	let flist = glob(prefix ? "*" .. prefix .. "*" : "*", 0, v:true)
+	let flist = glob(t:denote_directory .. prefix ? "*" .. prefix .. "*" : "*", 0, v:true)
 	let res = []
 	for filename in flist
 		let noteId = denote#meta#noteIdFromFile(filename)
@@ -34,7 +34,7 @@ function s:suggestions(base)
 		endif
 		let noteTitle = noteTitle ?? '(no title)'
 		let noteTags = denote#meta#noteTagsFromFile(filename)
-		let res = res->add({
+		call add(res, {
 					\ 'word' : 'denote:' .. noteId,
 					\ 'abbr' : noteTitle,
 					\ 'menu' : noteTags->join(', ')